485APOS 1 totalbondii485a122008.txt VANGUARD BOND INDEX FUNDS 485A ------------------------------------------------------------------------------- ------------------------------------------------------------------------------- SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM N-1A REGISTRATION STATEMENT (NO. 33-6001) UNDER THE SECURITIES ACT OF 1933 PRE-EFFECTIVE AMENDMENT NO. [ ] POST-EFFECTIVE AMENDMENT NO. 49 [X] AND REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940 AMENDMENT NO. 51 [X] VANGUARD BOND INDEX FUNDS (EXACT NAME OF REGISTRANT AS SPECIFIED IN DECLARATION OF TRUST) P.O. BOX 2600, VALLEY FORGE, PA 19482 (ADDRESS OF PRINCIPAL EXECUTIVE OFFICE) REGISTRANT'S TELEPHONE NUMBER (610) 669-1000 HEIDI STAM, ESQUIRE P.O. BOX 876 VALLEY FORGE, PA 19482 IT IS PROPOSED THAT THIS FILING WILL BECOME EFFECTIVE (CHECK APPROPRIATE BOX) [ ] IMMEDIATELY UPON FILING PURSUANT TO PARAGRAPH (B) [ ] ON (DATE) PURSUANT TO PARAGRAPH (B) [ ] 60 DAYS AFTER FILING PURSUANT TO PARAGRAPH (A)(1) [ ] ON (DATE) PURSUANT TO PARAGRAPH (A)(1) [X] 75 DAYS AFTER FILING PURSUANT TO PARAGRAPH (A)(2) [ ] ON (DATE), PURSUANT TO PARAGRAPH (A)(2) OF RULE 485 IF APPROPRIATE, CHECK THE FOLLOWING BOX: [ ] THIS POST-EFFECTIVE AMENDMENT DESIGNATES A NEW EFFECTIVE DATE FOR A PREVIOUSLY FILED POST-EFFECTIVE AMENDMENT. ------------------------------------------------------------------------------- ------------------------------------------------------------------------------- [SHIP LOGO VANGUARD /(R)/] VANGUARD TOTAL BOND MARKET II INDEX FUND PROSPECTUS January xx, 2009 Subject to Completion. Preliminary Prospectus dated December 24,2 008. -------------------------------------------------------------------------------- January xx, 2009 -------------------------------------------------------------------------------- Investor Shares Information contained in this prospectus is subject to completion or amendment. A registration statement for Vanguard Total Bond Market II Index Fund has been filed with the U.S. Securities and Exchange Commission but has not yet become effective. SHARES OF VANGUARD TOTAL BOND MARKET II INDEX FUND MAY NOT BE SOLD, NOR MAY OFFERS TO BUY BE ACCEPTED, PRIOR TO THE TIME THE REGISTRATION STATEMENT BECOMES EFFECTIVE. THIS COMMUNICATION SHALL NOT CONSTITUTE AN OFFER TO SELL, NOR SHALL THERE BE ANY SALE OF THESE SECURITIES IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION, OR SALE WOULD BE UNLAWFUL PRIOR TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS OF ANY SUCH STATE. This is the Fund's initial prospectus, so it contains no performance data. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense. CONTENTS

Fund Profile 1 Investing With Vanguard 17 ------------------------------------------------------------------------------- More on the Fund 4 Glossary of Investment Terms 18 ------------------------------------------------------------------------------- The Fund and Vanguard 13 ------------------------------------------------------------------------------- Investment Advisor 13 ------------------------------------------------------------------------------- Dividends, Capital Gains, and 14 Taxes ------------------------------------------------------------------------------- Share Price 16 -------------------------------------------------------------------------------

Why Reading This Prospectus Is Important This prospectus explains the investment objective, policies, strategies, and risks associated with the Fund. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk/(R)/ explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference. This Fund has been established by Vanguard as an investment vehicle for the Vanguard Target Retirement and Vanguard LifeStrategy Funds as well as certain trusts and accounts managed by Vanguard or its affiliates. The Fund is not available to other investors. Vanguard reserves the right to change the availability of the Fund or offer additional Funds at any time without prior notice to shareholders. Share Class Overview This prospectus offers the Fund's Investor Shares. A separate prospectus offers the Fund's Institutional Shares, which are for investors who generally do not require special employee benefit plan services and who invest a minimum of $5 million. The Fund's separate share classes have different expenses; as a result, their investment performances will differ. AN INVESTMENT IN THE FUND IS NOT A DEPOSIT OF A BANK AND IS NOT INSURED OR GUARANTEED BY THE FEDERAL DEPOSIT INSURANCE COMPANY OR ANY OTHER GOVERNMENT AGENCY. FUND PROFILE Investment Objective The Fund seeks to track the performance of a broad, market-weighted bond index. Primary Investment Strategies The Fund employs a "passive management"--or indexing--investment approach designed to track the performance of the Barclays Capital U.S. Aggregate Bond Index. This Index measures a wide spectrum of public, investment-grade, taxable, fixed income securities in the United States--including government, corporate, and international dollar-denominated bonds, as well as mortgage-backed and asset-backed securities--all with maturities of more than 1 year. The Fund invests by sampling the Index, meaning that it holds a broadly diversified collection of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund's investments will be selected through the sampling process, and at least 80% of the Fund's assets will be invested in bonds held in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index, which currently ranges between 5 and 10 years and, as of December 31, 2008, was x.x years. For additional information on the Fund's investment strategies, please see More on the Fund. Primary Risks An investment in the Fund could lose money over short or even long periods. You should expect the Fund's share price and total return to fluctuate within a wide range, like the fluctuations of the overall bond market. The Fund's performance could be hurt by: . Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests mainly in short- and intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds. . Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally moderate for intermediate-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly. . Credit risk, which is the chance that a bond issuer will fail to pay interest and principal in a timely manner, or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be low for the Fund because it purchases only bonds that are issued by the U.S. Treasury or are of investment-grade quality. . Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (repay) securities with higher coupons or interest rates before their maturity dates. The Fund would then lose potential price appreciation and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. For mortgage-backed securities, this risk is known as 1 prepayment risk. Call/prepayment risk should be moderate for the Fund because it invests only a portion of its assets in callable bonds and mortgage-backed securities. . Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Index. Index sampling risk for the Fund should be low. Performance/Risk Information The Fund began operations on January xx, 2009, so performance information for a full calendar year is not yet available. Fees and Expenses The following table describes the fees and expenses you may pay if you buy and hold Investor Shares of the Fund. As is the case with all mutual funds, transaction costs incurred by the Fund for buying and selling securities are not reflected in the table. However, these costs are reflected in investment performance figures. The expenses shown under Annual Fund Operating Expenses are based on estimated amounts for the current fiscal year. The Fund has no operating history; actual operating expenses could be different.

Shareholder Fees (Fees paid directly from your investment) ------------------------------------------------------------------------- Sales Charge (Load) Imposed on Purchases None ------------------------------------------------------------------------- Transaction Fee on Purchases None ------------------------------------------------------------------------- Sales Charge (Load) Imposed on Reinvested Dividends None ------------------------------------------------------------------------- Redemption Fee None ------------------------------------------------------------------------- Annual Fund Operating Expenses (Expenses deducted from the Fund's assets) ------------------------------------------------------------------------- Management Expenses 0.xx% ------------------------------------------------------------------------- 12b-1 Distribution Fee None ------------------------------------------------------------------------- Other Expenses 0.xx% ------------------------------------------------------------------------- Total Annual Fund Operating Expenses 0.19% -------------------------------------------------------------------------

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you invest $10,000 in the Fund's shares. This example assumes that the Fund provides a return of 5% a year and that operating expenses remain the same. The results apply whether or not you redeem your investment at the end of the given period. 2 1 Year 3 Years ---------------------------- $19 $61 ---------------------------- This example should not be considered to represent actual expenses or performance for the future. -------------------------------------------------------------------------------- PLAIN TALK ABOUT COSTS OF INVESTING Costs are an important consideration in choosing a mutual fund. That's because you, as a shareholder, pay the costs of operating a fund, plus any transaction costs incurred when the fund buys or sells securities. These costs can erode a substantial portion of the gross income or the capital appreciation a fund achieves. Even seemingly small differences in expenses can, over time, have a dramatic effect on a fund's performance. --------------------------------------------------------------------------------

Additional Information -------------------------------------------------------------------------------------------- Investment Advisor The Vanguard Group, Inc., Valley Forge, Pa., since inception -------------------------------------------------------------------------------------------- Dividends and Capital Gains Dividends are declared daily and distributed on the first business day of each month; capital gains, if any, are distributed annually in December. -------------------------------------------------------------------------------------------- Inception Date January xx, 2009 -------------------------------------------------------------------------------------------- Minimum Initial Investment $3,000 -------------------------------------------------------------------------------------------- Newspaper Abbreviation . -------------------------------------------------------------------------------------------- Vanguard Fund Number 635 -------------------------------------------------------------------------------------------- CUSIP Number . -------------------------------------------------------------------------------------------- Ticker Symbol . --------------------------------------------------------------------------------------------

3 MORE ON THE FUND This prospectus describes the primary risks you would face as a Fund shareholder. It is important to keep in mind one of the main axioms of investing: The higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: The lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance for fluctuations in the securities markets. Look for this [FLAG] symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. The following sections explain the primary investment strategies and policies that the Fund uses in pursuit of its objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. The Fund's policy of investing at least 80% of its assets in bonds that are part of its target index may be changed only upon 60 days' notice to shareholders. Market Exposure [FLAG] The Fund is subject to interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests mainly in short- and intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds. Although bonds are often thought to be less risky than stocks, there have been periods when bond prices have fallen significantly because of rising interest rates. For instance, prices of long-term bonds fell by almost 48% between December 1976 and September 1981. To illustrate the relationship between bond prices and interest rates, the following table shows the effect of a 1% and a 2% change (both up and down) in interest rates on the values of three noncallable bonds of different maturities, each with a face value of $1,000. 4

How Interest Rate Changes Affect the Value of a $1,000 Bond/1/ After a 1% After a 1% After a 2% After a 2% Type of Bond (Maturity) Increase Decrease Increase Decrease ------------------------------------------------------------------------------ Short-Term (2.5 years) $977 $1,024 $955 $1,048 ------------------------------------------------------------------------------ Intermediate-Term (10 years) 926 1,082 858 1,172 ------------------------------------------------------------------------------ Long-Term (20 years) 884 1,137 786 1,299 ------------------------------------------------------------------------------ 1 Assuming a 5% coupon.

These figures are for illustration only; you should not regard them as an indication of future performance of the bond market as a whole or the Fund in particular. -------------------------------------------------------------------------------- PLAIN TALK ABOUT BONDS AND INTEREST RATES As a rule, when interest rates rise, bond prices fall. The opposite is also true: Bond prices go up when interest rates fall. Why do bond prices and interest rates move in opposite directions? Let's assume that you hold a bond offering a 5% yield. A year later, interest rates are on the rise and bonds of comparable quality and maturity are offered with a 6% yield. With higher-yielding bonds available, you would have trouble selling your 5% bond for the price you paid--you would probably have to lower your asking price. On the other hand, if interest rates were falling and 4% bonds were being offered, you should be able to sell your 5% bond for more than you paid. How mortgage-backed securities are different: In general, declining interest rates will not lift the prices of mortgage-backed securities--such as GNMAs--as much as the prices of comparable bonds. Why? Because when interest rates fall, the bond market tends to discount the prices of mortgage-backed securities for prepayment risk--the possibility that homeowners will refinance their mortgages at lower rates and cause the bonds to be paid off prior to maturity. In part to compensate for this prepayment possibility, mortgage-backed securities tend to offer higher yields than other bonds of comparable credit quality and maturity. -------------------------------------------------------------------------------- Changes in interest rates can affect bond income as well as bond prices. [FLAG] The Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest in lower-yielding bonds. Income risk is generally moderate for intermediate-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly. 5 -------------------------------------------------------------------------------- PLAIN TALK ABOUT BOND MATURITIES A bond is issued with a specific maturity date--the date when the issuer must pay back the bond's principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bond's maturity, the more price risk you, as a bond investor, face as interest rates rise--but also the higher yield you could receive. Longer-term bonds are more suitable for investors willing to take a greater risk of price fluctuations to get higher and more stable interest income. Shorter-term bond investors should be willing to accept lower yields and greater income variability in return for less fluctuation in the value of their investment. -------------------------------------------------------------------------------- Although falling interest rates tend to strengthen bond prices, they can cause other sorts of problems for bond fund investors--bond calls and prepayments. [FLAG] The Fund is subject to call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (repay) securities with higher coupons or interest rates before their maturity dates. The Fund would then lose potential price appreciation and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. For mortgage-backed securities, this risk is known as prepayment risk. Because the Fund invests only a portion of its assets in callable bonds and mortgage-backed securities, call/prepayment risk for the Fund should be moderate. [FLAG] The Fund is subject to credit risk, which is the chance that a bond issuer will fail to pay interest and principal in a timely manner, or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. 6 -------------------------------------------------------------------------------- PLAIN TALK ABOUT CREDIT QUALITY A bond's credit-quality rating is an assessment of the issuer's ability to pay interest on the bond and, ultimately, to repay the principal. Credit quality is evaluated by one of the independent bond-rating agencies (for example, Moody's or Standard & Poor's) or through independent analysis conducted by a fund's advisor. The lower the rating, the greater the chance--in the rating agency's or advisor's opinion--that the bond issuer will default, or fail to meet its payment obligations. All things being equal, the lower a bond's credit rating, the higher its yield should be to compensate investors for assuming additional risk. Investment-grade bonds are those rated in one of the four highest ratings categories. A fund may treat an unrated bond as investment-grade if warranted by the advisor's analysis. -------------------------------------------------------------------------------- The credit quality of the Fund is expected to be very high, and thus credit risk should be low. The dollar-weighted average credit quality of the Fund's target index, as rated by Moody's Investors Service, Inc., was XXX, as of December 31, 2008 [FLAG] The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of its target index. Index sampling risk for the Fund should be low. To a limited extent, the Fund is also exposed to event risk, which is the chance that corporate fixed income securities held by the Fund may suffer a substantial decline in credit quality and market value because of a corporate restructuring or another corporate event. The Fund is generally managed without regard to tax ramifications. Security Selection Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all securities held in its target index--which is an indexing strategy called "replication"--the Fund uses index "sampling" techniques to select securities. Using sophisticated computer programs, the Fund selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include duration, cash flow, quality, and callability of the underlying bonds. In addition, the Fund keeps industry sector and subsector exposure within tight boundaries relative to its target index. Because the Fund does not hold all issues in its target index, some of the issues (and issuers) that are held will likely be overweighted (or underweighted) compared with the target index. The maximum 7 overweight (or underweight) is constrained at the issuer level with the goal of producing well-diversified credit in the portfolio. The number of bonds in the Fund's target index was xxxx, as of December 31, 2008. Types of bonds. The Fund's target index is the Barclays Capital U.S. Aggregate Bond Index. This Index measures the total universe of investment-grade fixed income securities in the United States--including government, corporate, and international dollar-denominated bonds, as well as mortgage-backed and asset-backed securities--all with maturities of more than 1 year. As of December 31, 2008, the Index was composed of the following types of bonds:

U.S. Corporate Mortgage- International Total Government Backed Dollar- /Agency Denominated ------------------------------------------------------------------------------------- Barclays Capital U.S. xx.x% xx.x% xx.x% x.x% 100% Aggregate Bond Index ---------------------------------------------------------------------------------------

An explanation of each type of bond follows: . U.S. government and agency bonds represent loans by investors to the U.S. Treasury Department or a wide variety of government agencies and instrumentalities. Securities issued by most U.S. government entities are neither guaranteed by the U.S. Treasury nor backed by the full faith and credit of the U.S. government. These entities include, among others, the Federal Home Loan Banks (FHLBs), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Mortgage Corporation (FHLMC). Securities issued by the U.S. Treasury and a small number of U.S. government agencies, such as the Government National Mortgage Association (GNMA), are backed by the full faith and credit of the U.S. government. . Corporate bonds are IOUs issued by businesses that want to borrow money for some purpose--often to develop a new product or service, to expand into a new market, or to buy another company. As with other types of bonds, the issuer promises to repay the principal on a specific date and to make interest payments in the meantime. The amount of interest offered depends both on market conditions and on the financial health of the corporation issuing the bonds; a company whose credit rating is not strong will have to offer a higher interest rate to obtain buyers for its bonds. For purposes of the preceding table, corporate bonds include securities that are backed by a pool of underlying assets (asset-backed securities) or commercial mortgages (commercial mortgage-backed bonds). The Fund expects to purchase only investment-grade corporate bonds. . Mortgage-backed securities represent interests in underlying pools of mortgages. Unlike ordinary bonds, which generally pay a fixed rate of interest at regular intervals and then repay principal upon maturity, mortgage-backed securities pass through both 8 interest and principal from underlying mortgages as part of their regular payments. Because the mortgages underlying the securities can be prepaid at any time by homeowners or by corporate borrowers, mortgage-backed securities are subject to prepayment risk. These types of securities are issued by a number of government agencies, including the GNMA, the FHLMC, and the FNMA. Mortgage-backed securities issued by GNMA are guaranteed by the full faith and credit of the U.S. government as to the timely payment of principal and interest; those issued by other government agencies or private corporations are not. The Fund may also invest in conventional mortgage-backed securities--which are packaged by private corporations and are not guaranteed by the U.S. government--and enter into mortgage-dollar-roll transactions. In a mortgage-dollar-roll transaction, the Fund sells mortgage-backed securities to a dealer and simultaneously agrees to purchase similar securities in the future at a predetermined price. These transactions simulate an investment in mortgage-backed securities and have the potential to enhance the Fund's returns and reduce its administrative burdens, compared with holding mortgage-backed securities directly. These transactions may increase the Fund's portfolio turnover rate. Mortgage dollar rolls will be used only to the extent that they are consistent with the Fund's investment objective and risk profile. . International dollar-denominated bonds are bonds denominated in U.S. dollars and issued by foreign governments and companies. To the extent that the Fund owns foreign bonds, it is subject to country risk, which is the chance that world events--such as political upheaval, financial troubles, or natural disasters--will adversely affect the value of securities issued by companies in foreign countries. In addition, the prices of foreign bonds and the prices of U.S. bonds have, at times, moved in opposite directions. Because the bond's value is designated in dollars rather than in the currency of the issuer's country, the investor is not exposed to currency risk; rather, the issuer assumes the risk, usually to attract U.S. investors. 9 -------------------------------------------------------------------------------- PLAIN TALK ABOUT U.S. GOVERNMENT-SPONSORED ENTITIES A variety of U.S. government-sponsored entities (GSEs), such as the Federal Home Loan Mortgage Corporation (FHLMC), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Banks (FHLBs), issue debt and mortgage-backed securities. Although GSEs may be chartered or sponsored by acts of Congress, they are not funded by congressional appropriations. In September of 2008, the U.S. Treasury placed FNMA and FHLMC under conservatorship and appointed the Federal Housing Finance Agency (FHFA) to manage their daily operations. In addition, the U.S. Treasury entered into purchase agreements with FNMA and FHLMC to provide them with capital in exchange for senior preferred stock. Generally, their securities are neither issued nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. government. In most cases, these securities are supported only by the credit of the GSE, standing alone. In some cases, a GSE's securities may be supported by the ability of the GSE to borrow from the Treasury, or may be supported by the U.S. government in some other way. Securities issued by the Government National Mortgage Association (GNMA), however, are backed by the full faith and credit of the U.S. government. -------------------------------------------------------------------------------- Other Investment Policies and Risks The Fund will invest at least 80% of its assets in bonds held in its target index. Up to 20% of the Fund's assets may be used to purchase nonpublic, investment-grade securities, generally referred to as 144A securities, as well as smaller public issues or medium-term notes not included in the index because of the small size of the issue. The vast majority of these securities will have characteristics and risks similar to those in the target index. Subject to the same 20% limit, the Fund may also purchase other investments that are outside of its target index or may hold bonds that, when acquired, were included in the index but subsequently were removed. The Fund may also invest in relatively conservative classes of collateralized mortgage obligations (CMOs), which offer a high degree of cash-flow predictability and a low level of vulnerability to mortgage prepayment risk. To reduce credit risk, these less-risky classes of CMOs are purchased only if they are issued by agencies of the U.S. government or issued by private companies that carry high-quality investment-grade ratings. The Fund reserves the right to substitute a different index for the index it currently tracks if the current index is discontinued, if the Fund's agreement with the sponsor of its target index is terminated, or for any other reason determined in good faith by the Fund's board of trustees. In any such instance, the substitute index would measure the same market segment as the current index. 10 [FLAG] The Fund may invest in derivatives. In general, derivatives may involve risks different from, and possibly greater than, those of the underlying securities, assets, or market indexes. Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, bond, or currency), a physical asset (such as gold), or a market index (such as the S&P 500 Index). The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. The advisor will not use derivatives to change the risk exposure of the Fund. In particular, derivatives will be used only where they may help the advisor: . Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment; . Add value when these instruments are attractively priced; or . Adjust sensitivity to changes in interest rates. The Fund's derivative investments may include fixed income futures contracts, fixed income options, interest rate swaps, total return swaps, credit default swaps, or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial--in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives. -------------------------------------------------------------------------------- PLAIN TALK ABOUT DERIVATIVES Derivatives can take many forms. Some forms of derivatives, such as exchange-traded futures and options on securities, commodities, or indexes, have been trading on regulated exchanges for decades. These types of derivatives are standardized contracts that can easily be bought and sold, and whose market values are determined and published daily. Nonstandardized derivatives (such as swap agreements), on the other hand, tend to be more specialized or complex, and may be harder to value. -------------------------------------------------------------------------------- Vanguard may invest a small portion of the Fund's assets in shares of bond exchange-traded funds (ETFs). ETFs provide returns similar to those of the bonds listed in the index or in a subset of the index. Vanguard may purchase ETFs when doing so will reduce the Fund's transaction costs or add value because the instruments are favorably priced. Vanguard receives no additional revenue from investing Fund assets in Vanguard bond ETFs because Fund assets invested in ETF Shares are excluded when allocating to the Fund its share of the costs of Vanguard operations. 11 Cash Management The Fund's daily cash balance may be invested in one or more Vanguard CMT Funds, which are very low-cost money market funds. When investing in a Vanguard CMT Fund, the Fund bears its proportionate share of the at-cost expenses of the CMT Fund in which it invests. Temporary Investment Measures The Fund may temporarily depart from its normal investment policies and strategies when doing so is believed to be in the Fund's best interest, so long as the alternative is consistent with the Fund's investment objective. For instance, the Fund may invest beyond the normal limits in derivatives or ETFs that are consistent with the Fund's objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately. Frequent Trading or Market-Timing Investors eligible to purchase shares of the Fund seek to maintain target asset allocations, which may require frequent rebalancing trades. Because the Fund is available only to such investors, the costs imposed by frequent trading are appropriately borne by the investors who cause them. For this reason, the board of trustees of the Fund has determined that it is not necessary to adopt policies and procedures designed to detect and deter frequent trading and market-timing in the Fund's shares. For information on frequent-trading limits of other Vanguard funds, please see the appropriate fund's prospectus. Turnover Rate Although the Fund normally seeks to invest for the long term, it may sell securities regardless of how long they have been held. -------------------------------------------------------------------------------- PLAIN TALK ABOUT TURNOVER RATE Turnover rate gives an indication of how transaction costs, which are not included in the fund's expense ratio, could affect the fund's future returns. In general, the greater the volume of buying and selling by the fund, the greater the impact that dealer markups and other transaction costs will have on its return. Also, funds with high turnover rates may be more likely to generate capital gains that must be distributed to shareholders as taxable income. -------------------------------------------------------------------------------- 12 The Fund and Vanguard The Fund is a member of The Vanguard Group, a family of 37 investment companies with more than 150 funds holding assets in excess of $990 billion. All of the funds that are members of The Vanguard Group share in the expenses associated with administrative services and business operations, such as personnel, office space, equipment, and advertising. Vanguard also provides marketing services to the funds. Although shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (or in the case of a fund with multiple share classes, each share class of the fund) pays its allocated share of The Vanguard Group's marketing costs. -------------------------------------------------------------------------------- PLAIN TALK ABOUT VANGUARD'S UNIQUE CORPORATE STRUCTURE The Vanguard Group is truly a mutual mutual fund company. It is owned jointly by the funds it oversees and thus indirectly by the shareholders in those funds. Most other mutual funds are operated by management companies that may be owned by one person, by a private group of individuals, or by public investors who own the management company's stock. The management fees charged by these companies include a profit component over and above the companies' cost of providing services. By contrast, Vanguard provides services to its member funds on an at-cost basis, with no profit component, which helps to keep the funds' expenses low. -------------------------------------------------------------------------------- Investment Advisor The Vanguard Group, Inc. (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Fixed Income Group. As of December 31, 2008, Vanguard served as advisor for approximately $xxx billion in assets. Vanguard manages the Fund on an at-cost basis, subject to the supervision and oversight of the trustees and officers of the Fund. For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the semiannual report to shareholders covering the fiscal period ended June 30, 2009, which will be available 60 days after that date. George U. Sauter, Chief Investment Officer and Managing Director of Vanguard. As Chief Investment Officer, he is responsible for the oversight of Vanguard's Quantitative Equity and Fixed Income Groups. The investments managed by these two groups include active quantitative equity funds, equity index funds, active bond funds, index bond funds, stable value portfolios, and money market funds. Since 13 joining Vanguard in 1987, Mr. Sauter has been a key contributor to the development of Vanguard's stock indexing and active quantitative equity investment strategies. He received his A.B. in Economics from Dartmouth College and an M.B.A. in Finance from the University of Chicago. Robert F. Auwaerter, Principal of Vanguard and head of Vanguard's Fixed Income Group. He has direct oversight responsibility for all money market funds, bond funds, and stable value portfolios managed by the Fixed Income Group. He has managed investment portfolios since 1978 and has been with Vanguard since 1981. He received his B.S. in Finance from The Wharton School of the University of Pennsylvania and an M.B.A. from Northwestern University. The managers primarily responsible for the day-to-day management of the Fund are: Kenneth E. Volpert, CFA, Principal of Vanguard and head of Vanguard's Taxable Bond Group. He has managed investment portfolios since 1982; has been with Vanguard since 1992; and has co-managed the Total Bond Market II Index Fund since 2009. Education: B.S., University of Illinois; M.B.A., University of Chicago. Gregory Davis, CFA, Principal of Vanguard, head of Vanguard's Bond Index Group, and Portfolio Manager for Vanguard. He has worked in investment management for Vanguard since 1999; has managed investment portfolios since 2000; and has co-managed the Total Bond Market II Index Fund since 2009. Education: B.S., Pennsylvania State University; M.B.A.,The Wharton School of the University of Pennsylvania. The Statement of Additional Information provides information about each portfolio manager's compensation, other accounts under management, and ownership of securities in the Fund. Dividends, Capital Gains, and Taxes Fund Distributions The Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net capital gains realized from the sale of its holdings. The Fund's income dividends accrue daily and are distributed on the first business day of every month; capital gains distributions generally occur annually in December. In addition, the Fund may occasionally make supplemental distributions at some other time during the year. You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund. 14 -------------------------------------------------------------------------------- PLAIN TALK ABOUT DISTRIBUTIONS As a shareholder, you are entitled to your portion of a fund's income from interest as well as capital gains from the fund's sale of investments. Income consists of interest the fund earns from its money market and bond investments. Capital gains are realized whenever the fund sells securities for higher prices than it paid for them. These capital gains are either short-term or long-term, depending on whether the fund held the securities for one year or less or for more than one year. -------------------------------------------------------------------------------- Basic Tax Points Vanguard will send you a statement each year showing the tax status of all your distributions. In addition, investors in taxable accounts should be aware of the following basic federal income tax points: . Distributions are taxable to you whether or not you reinvest these amounts in additional Fund shares. . Distributions declared in December--if paid to you by the end of January--are taxable as if received in December. . Any dividend and short-term capital gains distributions that you receive are taxable to you as ordinary income. . Any distributions of net long-term capital gains are taxable to you as long-term capital gains, no matter how long you've owned shares in the Fund. . Capital gains distributions may vary considerably from year to year as a result of the Fund's normal investment activities and cash flows. . A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return. Dividend and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes. Depending on your state's rules, however, any dividends attributable to interest earned on direct obligations of the U.S. government may be exempt from state and local taxes. Vanguard will notify you each year how much, if any, of your dividends may qualify for this exemption. General Information Backup withholding. By law, Vanguard must withhold 28% of any taxable distributions or redemptions from your account if you do not: . Provide us with your correct taxpayer identification number; . Certify that the taxpayer identification number is correct; and 15 . Confirm that you are not subject to backup withholding. Similarly, Vanguard must withhold taxes from your account if the IRS instructs us to do so. Foreign investors. Vanguard funds generally are not sold outside the United States, except to certain qualified investors. If you reside outside the United States, please consult our website at www.vanguard.com and review "Non-U.S. investors." Foreign investors should be aware that U.S. withholding and estate taxes may apply to any investments in Vanguard funds. Invalid addresses. If a dividend or capital gains distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest all future distributions until you provide us with a valid mailing address. Tax consequences. This prospectus provides general tax information only. If you are investing through a tax-deferred retirement account, such as an IRA, special tax rules apply. Please consult your tax advisor for detailed information about a fund's tax consequences for you. Share Price Share price, also known as net asset value (NAV), is calculated each business day as of the close of regular trading on the New York Stock Exchange, generally 4 p.m., Eastern time. Each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to each share class by the number of Fund shares outstanding for that class. On holidays or other days when the Exchange is closed, the NAV is not calculated, and the Fund does not transact purchase or redemption requests. Debt securities held by a Vanguard fund are valued based on information furnished by an independent pricing service or market quotations. Certain short-term debt instruments used to manage a fund's cash are valued on the basis of amortized cost. The values of any mutual fund shares held by a fund are based on the NAVs of the shares. The values of any ETF or closed-end fund shares held by a fund are based on the market value of the shares. When the fund determines that pricing-service information or market quotations either are not readily available or do not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security). A fund also may use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day). 16 Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities. Vanguard fund share prices can be found daily in the mutual fund listings of most major newspapers under various "Vanguard" headings. Investing With Vanguard Vanguard Total Bond Market II Index Fund has been established by Vanguard as an investment vehicle for the Vanguard Target Retirement and Vanguard LifeStrategy Funds as well as certain trusts and accounts managed by Vanguard or its affiliates. The Fund is not available to other investors. Vanguard reserves the right to change the availability of the Fund or offer additional Funds at any time without prior notice to shareholders. Purchases, redemptions, and exchanges of shares issued by Vanguard Total Bond Market II Index Fund are conducted by Vanguard or its affiliates on behalf of the participating funds, trusts, and accounts. In all cases, transactions will be based on the Fund's next-determined NAV after Vanguard receives the request (or, in the case of new contributions, the next-determined NAV after Vanguard receives the order). As long as this request is received before the close of trading on the New York Stock Exchange, generally 4 p.m., Eastern time, the investor will receive that day's NAV. This is known as the trade date. Transaction requests received after that time receive a trade date of the first business day following the date of receipt. The trade date may vary, depending on the method of payment for the transaction. Portfolio Holdings We generally post on our website at www.vanguard.com, in the Holdings section of the Fund's Profile page, a detailed list of the securities held by the Fund (under Portfolio Holdings), as of the most recent calendar-quarter-end. This list is generally updated within 30 days after the end of each calendar quarter. Vanguard may exclude any portion of these portfolio holdings from publication when deemed in the best interest of the Fund. Please consult the Fund's Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund's portfolio holdings.CFA/(R)/ is a trademark owned by CFA Institute. Standard & Poor's/(R)/,S&P/(R)/, S&P 500/(R)/, Standard & Poor's 500, and 500 are trademarks of The McGraw-Hill Companies, Inc., and have been licensed for use by The Vanguard Group, Inc. Vanguard mutual funds are not sponsored, endorsed, sold, or promoted by Standard & Poor's, and Standard & Poor's makes no representation regarding the advisability of investing in the funds. 17 GLOSSARY OF INVESTMENT TERMS Active Management. An investment approach that seeks to exceed the average returns of the financial markets. Active managers rely on research, market forecasts, and their own judgment and experience in selecting securities to buy and sell. Bond. A debt security (IOU) issued by a corporation, government, or government agency in exchange for the money you lend it. In most instances, the issuer agrees to pay back the loan by a specific date and make regular interest payments until that date. Capital Gains Distribution. Payment to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses. Corporate Bond. An IOU issued by a business that wants to borrow money. As with other types of bonds, the issuer promises to repay the borrowed money on a specific date and to make interest payments in the meantime. Coupon. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security. Dividend Distribution. Payment to mutual fund shareholders of income from interest or dividends generated by a fund's investments. Expense Ratio. The percentage of a fund's average net assets used to pay its expenses during a fiscal year. The expense ratio includes management expenses--such as advisory fees, account maintenance, reporting, accounting, legal, and other administrative expenses--and any 12b-1 distribution fees. It does not include the transaction costs of buying and selling portfolio securities. Face Value. The amount to be paid at a bond's maturity; also known as the par value or principal. Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower must pay a fixed, variable, or floating rate of interest. Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund's investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is measured from the inception date. International Dollar-Denominated Bond. A bond denominated in U.S. dollars issued by foreign governments and companies. Because the bond's value is designated in dollars, an investor is not exposed to foreign-currency risk. 18 Investment-Grade Bond. A debt security whose credit quality is considered by independent bond-rating agencies, or through independent analysis conducted by a fund's advisor, to be sufficient to ensure timely payment of principal and interest under current economic circumstances. Debt securities rated in one of the four highest rating categories are considered "investment-grade." Other debt securities may be considered by the advisor to be investment-grade. Mortgage-Backed Security. A bond or pass-through certificate that represents an interest in an underlying pool of mortgages and is issued by various government agencies or private corporations. Unlike ordinary fixed income securities, mortgage-backed securities include both interest and principal as part of their regular payments. Passive Management. A low-cost investment strategy in which a mutual fund attempts to track--rather than outperform--a specified market benchmark or "index"; also known as indexing. Securities. Stocks, bonds, money market instruments, and other investment vehicles. Total Return. A percentage change, over a specified time period, in a mutual fund's net asset value, assuming the reinvestment of all distributions of dividends and capital gains. Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund's volatility, the wider the fluctuations in its returns. Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment's price. 19 This page intentionally left blank. This page intentionally left blank. [SHIP LOGO VANGUARD /(R)/] P.O. Box 2600 Valley Forge, PA 19482-2600 CONNECT WITH VANGUARD/(R)/ > www.vanguard.com For More Information If you would like more information about Vanguard Total Bond Market II Index Fund, the following documents are available free upon request: Annual/Semiannual Reports to Shareholders Additional information about the Fund's investments will be available in the Fund's annual and semiannual reports to shareholders. In the annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. Statement of Additional Information (SAI) The SAI provides more detailed information about the Fund. The SAI is incorporated by reference into (and is thus legally a part of) this prospectus. To receive a free copy of the latest annual or semiannual report (once available) or the SAI, or to request additional information about the Fund or other Vanguard funds, please visit www.vanguard.com or contact us as follows: The Vanguard Group Investor Information Department P.O. Box 2900 Valley Forge, PA 19482-2900 Telephone: 800-662-7447 (SHIP); Text telephone for people with hearing impairment: 800-952-3335 If you are a current Vanguard shareholder and would like information about your account, account transactions, and/or account statements, please call: Client Services Department Telephone: 800-662-2739 (CREW); Text telephone for people with hearing impairment: 800-749-7273 Information Provided by the Securities and Exchange Commission (SEC) You can review and copy information about the Fund (including the SAI) at the SEC's Public Reference Room in Washington, DC. To find out more about this public service, call the SEC at 202-551-8090. Reports and other information about the Fund are also available in the EDGAR database on the SEC's Internet site at www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following e-mail address: publicinfo@sec.gov, or by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-0102. Fund's Investment Company Act file number: 811-4681 (C) 2009 The Vanguard Group, Inc. All rights reserved. Vanguard Marketing Corporation, Distributor. P635 012009 [SHIP LOGO VANGUARD /(R)/] VANGUARD TOTAL BOND MARKET II INDEX FUND PROSPECTUS January xx, 2009 Subject to Completion. Preliminary Prospectus dated December 24,2 008. -------------------------------------------------------------------------------- January xx, 2009 -------------------------------------------------------------------------------- Institutional Shares Information contained in this prospectus is subject to completion or amendment. A registration statement for Vanguard Total Bond Market II Index Fund has been filed with the U.S. Securities and Exchange Commission but has not yet become effective. Shares of Vanguard Total Bond Market II Index Fund may not be sold, nor may offers to buy be accepted, prior to the time the registration statement becomes effective. This communication shall not constitute an offer to sell, nor shall there be any sale of these securities in any state in which such offer, solicitation, or sale would be unlawful prior to registration or qualification under the securities laws of any such state. This is the Fund's initial prospectus, so it contains no performance data. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense. CONTENTS

Fund Profile 1 Investing With Vanguard 17 ------------------------------------------------------------------------------- More on the Fund 4 Glossary of Investment Terms 18 ------------------------------------------------------------------------------- The Fund and Vanguard 13 ------------------------------------------------------------------------------- Investment Advisor 13 ------------------------------------------------------------------------------- Dividends, Capital Gains, and 14 Taxes ------------------------------------------------------------------------------- Share Price 16 -------------------------------------------------------------------------------

Why Reading This Prospectus Is Important This prospectus explains the investment objective, policies, strategies, and risks associated with the Fund. To highlight terms and concepts important to mutual fund investors, we have provided Plain Talk/(R)/ explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference. THIS FUND HAS BEEN ESTABLISHED BY VANGUARD AS AN INVESTMENT VEHICLE FOR THE VANGUARD TARGET RETIREMENT AND VANGUARD LIFESTRATEGY FUNDS AS WELL AS CERTAIN TRUSTS AND ACCOUNTS MANAGED BY VANGUARD OR ITS AFFILIATES. THE FUND IS NOT AVAILABLE TO OTHER INVESTORS. VANGUARD RESERVES THE RIGHT TO CHANGE THE AVAILABILITY OF THE FUND OR OFFER ADDITIONAL FUNDS AT ANY TIME WITHOUT PRIOR NOTICE TO SHAREHOLDERS. Share Class Overview This prospectus offers the Fund's Institutional Shares. A separate prospectus offers the Fund's Investor Shares, which have an investment minimum of $3,000. The Fund's separate share classes have different expenses; as a result, their investment performances will differ. AN INVESTMENT IN THE FUND IS NOT A DEPOSIT OF A BANK AND IS NOT INSURED OR GUARANTEED BY THE FEDERAL DEPOSIT INSURANCE COMPANY OR ANY OTHER GOVERNMENT AGENCY. FUND PROFILE Investment Objective The Fund seeks to track the performance of a broad, market-weighted bond index.. Primary Investment Strategies The Fund employs a "passive management"--or indexing--investment approach designed to track the performance of the Barclays Capital U.S. Aggregate Bond Index. This Index measures a wide spectrum of public, investment-grade, taxable, fixed income securities in the United States--including government, corporate, and international dollar-denominated bonds, as well as mortgage-backed and asset-backed securities--all with maturities of more than 1 year. The Fund invests by sampling the Index, meaning that it holds a broadly diversified collection of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. All of the Fund's investments will be selected through the sampling process, and at least 80% of the Fund's assets will be invested in bonds held in the Index. The Fund maintains a dollar-weighted average maturity consistent with that of the Index, which currently ranges between 5 and 10 years and, as of December 31, 2008, was x.x years. For additional information on the Fund's investment strategies, please see More on the Fund. Primary Risks An investment in the Fund could lose money over short or even long periods. You should expect the Fund's share price and total return to fluctuate within a wide range, like the fluctuations of the overall bond market. The Fund's performance could be hurt by: . Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests mainly in short- and intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds. . Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally moderate for intermediate-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly. . Credit risk, which is the chance that a bond issuer will fail to pay interest and principal in a timely manner, or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. Credit risk should be low for the Fund because it purchases only bonds that are issued by the U.S. Treasury or are of investment-grade quality. . Call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (repay) securities with higher coupons or interest rates before their maturity dates. The Fund would then lose potential price appreciation and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. For mortgage-backed securities, this risk is known as 1 prepayment risk. Call/prepayment risk should be moderate for the Fund because it invests only a portion of its assets in callable bonds and mortgage-backed securities. . Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Index. Index sampling risk for the Fund should be low. Performance/Risk Information The Fund began operations on January xx, 2009, so performance information for a full calendar year is not yet available. Fees and Expenses The following table describes the fees and expenses you may pay if you buy and hold Institutional Shares of the Fund. As is the case with all mutual funds, transaction costs incurred by the Fund for buying and selling securities are not reflected in the table. However, these costs are reflected in investment performance figures. The expenses shown under Annual Fund Operating Expenses are based on estimated amounts for the current fiscal year. The Fund has no operating history; actual operating expenses could be different.

Shareholder Fees (Fees paid directly from your investment) ------------------------------------------------------------------------- Sales Charge (Load) Imposed on Purchases None ------------------------------------------------------------------------- Transaction Fee on Purchases None ------------------------------------------------------------------------- Sales Charge (Load) Imposed on Reinvested Dividends None ------------------------------------------------------------------------- Redemption Fee None ------------------------------------------------------------------------- Annual Fund Operating Expenses (Expenses deducted from the Fund's assets) ------------------------------------------------------------------------- Management Expenses 0.xx% ------------------------------------------------------------------------- 12b-1 Distribution Fee None ------------------------------------------------------------------------- Other Expenses 0.xx% ------------------------------------------------------------------------- Total Annual Fund Operating Expenses 0.07% -------------------------------------------------------------------------

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. It illustrates the hypothetical expenses that you would incur over various periods if you invest $10,000 in the Fund's shares. This example assumes that the Fund provides a return of 5% a year and that operating expenses remain the same. The results apply whether or not you redeem your investment at the end of the given period. 2 1 Year 3 Years ---------------------------- $7 $23 ---------------------------- This example should not be considered to represent actual expenses or performance for the future. -------------------------------------------------------------------------------- PLAIN TALK ABOUT COSTS OF INVESTING Costs are an important consideration in choosing a mutual fund. That's because you, as a shareholder, pay the costs of operating a fund, plus any transaction costs incurred when the fund buys or sells securities. These costs can erode a substantial portion of the gross income or the capital appreciation a fund achieves. Even seemingly small differences in expenses can, over time, have a dramatic effect on a fund's performance. --------------------------------------------------------------------------------

Additional Information -------------------------------------------------------------------------------------------- Investment Advisor The Vanguard Group, Inc., Valley Forge, Pa., since inception -------------------------------------------------------------------------------------------- Dividends and Capital Gains Dividends are declared daily and distributed on the first business day of each month; capital gains, if any, are distributed annually in December. -------------------------------------------------------------------------------------------- Inception Date Investor Shares-January xx, 2009 Institutional Shares-January xx, 2009 -------------------------------------------------------------------------------------------- Minimum Initial Investment $5 million -------------------------------------------------------------------------------------------- Newspaper Abbreviation . -------------------------------------------------------------------------------------------- Vanguard Fund Number 660 -------------------------------------------------------------------------------------------- CUSIP Number . -------------------------------------------------------------------------------------------- Ticker Symbol . --------------------------------------------------------------------------------------------

3 MORE ON THE FUND This prospectus describes the primary risks you would face as a Fund shareholder. It is important to keep in mind one of the main axioms of investing: The higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: The lower the risk, the lower the potential reward. As you consider an investment in any mutual fund, you should take into account your personal tolerance for fluctuations in the securities markets. Look for this [FlAG] symbol throughout the prospectus. It is used to mark detailed information about the more significant risks that you would confront as a Fund shareholder. The following sections explain the primary investment strategies and policies that the Fund uses in pursuit of its objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. The Fund's policy of investing at least 80% of its assets in bonds that are part of its target index may be changed only upon 60 days' notice to shareholders. Market Exposure [FLAG] The Fund is subject to interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates. Interest rate risk should be moderate for the Fund because it invests mainly in short- and intermediate-term bonds, whose prices are less sensitive to interest rate changes than are the prices of long-term bonds. Although bonds are often thought to be less risky than stocks, there have been periods when bond prices have fallen significantly because of rising interest rates. For instance, prices of long-term bonds fell by almost 48% between December 1976 and September 1981. To illustrate the relationship between bond prices and interest rates, the following table shows the effect of a 1% and a 2% change (both up and down) in interest rates on the values of three noncallable bonds of different maturities, each with a face value of $1,000. 4

How Interest Rate Changes Affect the Value of a $1,000 Bond/1/ After a 1% After a 1% After a 2% After a 2% Type of Bond (Maturity) Increase Decrease Increase Decrease ------------------------------------------------------------------------------ Short-Term (2.5 years) $977 $1,024 $955 $1,048 ------------------------------------------------------------------------------ Intermediate-Term (10 years) 926 1,082 858 1,172 ------------------------------------------------------------------------------ Long-Term (20 years) 884 1,137 786 1,299 ------------------------------------------------------------------------------ 1 Assuming a 5% coupon.

These figures are for illustration only; you should not regard them as an indication of future performance of the bond market as a whole or the Fund in particular. -------------------------------------------------------------------------------- PLAIN TALK ABOUT BONDS AND INTEREST RATES As a rule, when interest rates rise, bond prices fall. The opposite is also true: Bond prices go up when interest rates fall. Why do bond prices and interest rates move in opposite directions? Let's assume that you hold a bond offering a 5% yield. A year later, interest rates are on the rise and bonds of comparable quality and maturity are offered with a 6% yield. With higher-yielding bonds available, you would have trouble selling your 5% bond for the price you paid--you would probably have to lower your asking price. On the other hand, if interest rates were falling and 4% bonds were being offered, you should be able to sell your 5% bond for more than you paid. How mortgage-backed securities are different: In general, declining interest rates will not lift the prices of mortgage-backed securities--such as GNMAs--as much as the prices of comparable bonds. Why? Because when interest rates fall, the bond market tends to discount the prices of mortgage-backed securities for prepayment risk--the possibility that homeowners will refinance their mortgages at lower rates and cause the bonds to be paid off prior to maturity. In part to compensate for this prepayment possibility, mortgage-backed securities tend to offer higher yields than other bonds of comparable credit quality and maturity. -------------------------------------------------------------------------------- Changes in interest rates can affect bond income as well as bond prices. [FLAG] The Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest in lower-yielding bonds. Income risk is generally moderate for intermediate-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly. 5 -------------------------------------------------------------------------------- PLAIN TALK ABOUT BOND MATURITIES A bond is issued with a specific maturity date--the date when the issuer must pay back the bond's principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bond's maturity, the more price risk you, as a bond investor, face as interest rates rise--but also the higher yield you could receive. Longer-term bonds are more suitable for investors willing to take a greater risk of price fluctuations to get higher and more stable interest income. Shorter-term bond investors should be willing to accept lower yields and greater income variability in return for less fluctuation in the value of their investment. -------------------------------------------------------------------------------- Although falling interest rates tend to strengthen bond prices, they can cause other sorts of problems for bond fund investors--bond calls and prepayments. [FLAG] The Fund is subject to call risk, which is the chance that during periods of falling interest rates, issuers of callable bonds may call (repay) securities with higher coupons or interest rates before their maturity dates. The Fund would then lose potential price appreciation and would be forced to reinvest the unanticipated proceeds at lower interest rates, resulting in a decline in the Fund's income. For mortgage-backed securities, this risk is known as prepayment risk. Because the Fund invests only a portion of its assets in callable bonds and mortgage-backed securities, call/prepayment risk for the Fund should be moderate. [FLAG] The Fund is subject to credit risk, which is the chance that a bond issuer will fail to pay interest and principal in a timely manner, or that negative perceptions of the issuer's ability to make such payments will cause the price of that bond to decline. 6 -------------------------------------------------------------------------------- PLAIN TALK ABOUT CREDIT QUALITY A bond's credit-quality rating is an assessment of the issuer's ability to pay interest on the bond and, ultimately, to repay the principal. Credit quality is evaluated by one of the independent bond-rating agencies (for example, Moody's or Standard & Poor's) or through independent analysis conducted by a fund's advisor. The lower the rating, the greater the chance--in the rating agency's or advisor's opinion--that the bond issuer will default, or fail to meet its payment obligations. All things being equal, the lower a bond's credit rating, the higher its yield should be to compensate investors for assuming additional risk. Investment-grade bonds are those rated in one of the four highest ratings categories. A fund may treat an unrated bond as investment-grade if warranted by the advisor's analysis. -------------------------------------------------------------------------------- The credit quality of the Fund is expected to be very high, and thus credit risk should be low. The dollar-weighted average credit quality of the Fund's target index, as rated by Moody's Investors Service, Inc., was xxx, as of December 31, 2008. [FLAG] The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of its target index. Index sampling risk for the Fund should be low. To a limited extent, the Fund is also exposed to event risk, which is the chance that corporate fixed income securities held by the Fund may suffer a substantial decline in credit quality and market value because of a corporate restructuring or another corporate event. The Fund is generally managed without regard to tax ramifications. Security Selection Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all securities held in its target index--which is an indexing strategy called "replication"--the Fund uses index "sampling" techniques to select securities. Using sophisticated computer programs, the Fund selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include duration, cash flow, quality, and callability of the underlying bonds. In addition, the Fund keeps industry sector and subsector exposure within tight boundaries relative to its target index. Because the Fund does not hold all issues in its target index, some of the issues (and issuers) that are held will likely be overweighted (or underweighted) compared with the target index. The maximum 7 overweight (or underweight) is constrained at the issuer level with the goal of producing well-diversified credit in the portfolio. The number of bonds in the Fund's target index was xxx, as of December 31, 2008. Types of bonds. The Fund's target index is the Barclays Capital U.S. Aggregate Bond Index. This Index measures the total universe of investment-grade fixed income securities in the United States--including government, corporate, and international dollar-denominated bonds, as well as mortgage-backed and asset-backed securities--all with maturities of more than 1 year. As of December 31, 2008, the Index was composed of the following types of bonds:

U.S. Corporate Mortgage- International Total Government Backed Dollar- /Agency Denominated ------------------------------------------------------------------------------------- Barclays Capital U.S. xx.x% xx.x% xx.x% x.x% 100% Aggregate Bond Index ---------------------------------------------------------------------------------------

An explanation of each type of bond follows: . U.S. government and agency bonds represent loans by investors to the U.S. Treasury Department or a wide variety of government agencies and instrumentalities. Securities issued by most U.S. government entities are neither guaranteed by the U.S. Treasury nor backed by the full faith and credit of the U.S. government. These entities include, among others, the Federal Home Loan Banks (FHLBs), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Mortgage Corporation (FHLMC). Securities issued by the U.S. Treasury and a small number of U.S. government agencies, such as the Government National Mortgage Association (GNMA), are backed by the full faith and credit of the U.S. government. . Corporate bonds are IOUs issued by businesses that want to borrow money for some purpose--often to develop a new product or service, to expand into a new market, or to buy another company. As with other types of bonds, the issuer promises to repay the principal on a specific date and to make interest payments in the meantime. The amount of interest offered depends both on market conditions and on the financial health of the corporation issuing the bonds; a company whose credit rating is not strong will have to offer a higher interest rate to obtain buyers for its bonds. For purposes of the preceding table, corporate bonds include securities that are backed by a pool of underlying assets (asset-backed securities) or commercial mortgages (commercial mortgage-backed bonds). The Fund expects to purchase only investment-grade corporate bonds. . Mortgage-backed securities represent interests in underlying pools of mortgages. Unlike ordinary bonds, which generally pay a fixed rate of interest at regular intervals and then repay principal upon maturity, mortgage-backed securities pass through both 8 interest and principal from underlying mortgages as part of their regular payments. Because the mortgages underlying the securities can be prepaid at any time by homeowners or by corporate borrowers, mortgage-backed securities are subject to prepayment risk. These types of securities are issued by a number of government agencies, including the GNMA, the FHLMC, and the FNMA. Mortgage-backed securities issued by GNMA are guaranteed by the full faith and credit of the U.S. government as to the timely payment of principal and interest; those issued by other government agencies or private corporations are not. The Fund may also invest in conventional mortgage-backed securities--which are packaged by private corporations and are not guaranteed by the U.S. government--and enter into mortgage-dollar-roll transactions. In a mortgage-dollar-roll transaction, the Fund sells mortgage-backed securities to a dealer and simultaneously agrees to purchase similar securities in the future at a predetermined price. These transactions simulate an investment in mortgage-backed securities and have the potential to enhance the Fund's returns and reduce its administrative burdens, compared with holding mortgage-backed securities directly. These transactions may increase the Fund's portfolio turnover rate. Mortgage dollar rolls will be used only to the extent that they are consistent with the Fund's investment objective and risk profile. . International dollar-denominated bonds are bonds denominated in U.S. dollars and issued by foreign governments and companies. To the extent that the Fund owns foreign bonds, it is subject to country risk, which is the chance that world events--such as political upheaval, financial troubles, or natural disasters--will adversely affect the value of securities issued by companies in foreign countries. In addition, the prices of foreign bonds and the prices of U.S. bonds have, at times, moved in opposite directions. Because the bond's value is designated in dollars rather than in the currency of the issuer's country, the investor is not exposed to currency risk; rather, the issuer assumes the risk, usually to attract U.S. investors. 9 -------------------------------------------------------------------------------- PLAIN TALK ABOUT U.S. GOVERNMENT-SPONSORED ENTITIES A variety of U.S. government-sponsored entities (GSEs), such as the Federal Home Loan Mortgage Corporation (FHLMC), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Banks (FHLBs), issue debt and mortgage-backed securities. Although GSEs may be chartered or sponsored by acts of Congress, they are not funded by congressional appropriations. In September of 2008, the U.S. Treasury placed FNMA and FHLMC under conservatorship and appointed the Federal Housing Finance Agency (FHFA) to manage their daily operations. In addition, the U.S. Treasury entered into purchase agreements with FNMA and FHLMC to provide them with capital in exchange for senior preferred stock. Generally, their securities are neither issued nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. government. In most cases, these securities are supported only by the credit of the GSE, standing alone. In some cases, a GSE's securities may be supported by the ability of the GSE to borrow from the Treasury, or may be supported by the U.S. government in some other way. Securities issued by the Government National Mortgage Association (GNMA), however, are backed by the full faith and credit of the U.S. government. -------------------------------------------------------------------------------- Other Investment Policies and Risks The Fund will invest at least 80% of its assets in bonds held in its target index. Up to 20% of the Fund's assets may be used to purchase nonpublic, investment-grade securities, generally referred to as 144A securities, as well as smaller public issues or medium-term notes not included in the index because of the small size of the issue. The vast majority of these securities will have characteristics and risks similar to those in the target index. Subject to the same 20% limit, the Fund may also purchase other investments that are outside of its target index or may hold bonds that, when acquired, were included in the index but subsequently were removed. The Fund may also invest in relatively conservative classes of collateralized mortgage obligations (CMOs), which offer a high degree of cash-flow predictability and a low level of vulnerability to mortgage prepayment risk. To reduce credit risk, these less-risky classes of CMOs are purchased only if they are issued by agencies of the U.S. government or issued by private companies that carry high-quality investment-grade ratings. The Fund reserves the right to substitute a different index for the index it currently tracks if the current index is discontinued, if the Fund's agreement with the sponsor of its target index is terminated, or for any other reason determined in good faith by the Fund's board of trustees. In any such instance, the substitute index would measure the same market segment as the current index. 10 [FLAG] The Fund may invest in derivatives. In general, derivatives may involve risks different from, and possibly greater than, those of the underlying securities, assets, or market indexes. Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, bond, or currency), a physical asset (such as gold), or a market index (such as the S&P 500 Index). The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. The advisor will not use derivatives to change the risk exposure of the Fund. In particular, derivatives will be used only where they may help the advisor: . Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment; . Add value when these instruments are attractively priced; or . Adjust sensitivity to changes in interest rates. The Fund's derivative investments may include fixed income futures contracts, fixed income options, interest rate swaps, total return swaps, credit default swaps, or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial--in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives. -------------------------------------------------------------------------------- PLAIN TALK ABOUT DERIVATIVES Derivatives can take many forms. Some forms of derivatives, such as exchange-traded futures and options on securities, commodities, or indexes, have been trading on regulated exchanges for decades. These types of derivatives are standardized contracts that can easily be bought and sold, and whose market values are determined and published daily. Nonstandardized derivatives (such as swap agreements), on the other hand, tend to be more specialized or complex, and may be harder to value. -------------------------------------------------------------------------------- Vanguard may invest a small portion of the Fund's assets in shares of bond exchange-traded funds (ETFs). ETFs provide returns similar to those of the bonds listed in the index or in a subset of the index. Vanguard may purchase ETFs when doing so will reduce the Fund's transaction costs or add value because the instruments are favorably priced. Vanguard receives no additional revenue from investing Fund assets in Vanguard bond ETFs because Fund assets invested in ETF Shares are excluded when allocating to the Fund its share of the costs of Vanguard operations. 11 Cash Management The Fund's daily cash balance may be invested in one or more Vanguard CMT Funds, which are very low-cost money market funds. When investing in a Vanguard CMT Fund, the Fund bears its proportionate share of the at-cost expenses of the CMT Fund in which it invests. Temporary Investment Measures The Fund may temporarily depart from its normal investment policies and strategies when doing so is believed to be in the Fund's best interest, so long as the alternative is consistent with the Fund's investment objective. For instance, the Fund may invest beyond the normal limits in derivatives or ETFs that are consistent with the Fund's objective when those instruments are more favorably priced or provide needed liquidity, as might be the case when the Fund receives large cash flows that it cannot prudently invest immediately. Frequent Trading or Market-Timing Investors eligible to purchase shares of the Fund seek to maintain target asset allocations, which may require frequent rebalancing trades. Because the Fund is available only to such investors, the costs imposed by frequent trading are appropriately borne by the investors who cause them. For this reason, the board of trustees of the Fund has determined that it is not necessary to adopt policies and procedures designed to detect and deter frequent trading and market-timing in the Fund's shares. For information on frequent-trading limits of other Vanguard funds, please see the appropriate fund's prospectus. Turnover Rate Although the Fund normally seeks to invest for the long term, it may sell securities regardless of how long they have been held. -------------------------------------------------------------------------------- PLAIN TALK ABOUT TURNOVER RATE Turnover rate gives an indication of how transaction costs, which are not included in the fund's expense ratio, could affect the fund's future returns. In general, the greater the volume of buying and selling by the fund, the greater the impact that dealer markups and other transaction costs will have on its return. Also, funds with high turnover rates may be more likely to generate capital gains that must be distributed to shareholders as taxable income. -------------------------------------------------------------------------------- 12 The Fund and Vanguard The Fund is a member of The Vanguard Group, a family of 37 investment companies with more than 150 funds holding assets in excess of $990 billion. All of the funds that are members of The Vanguard Group share in the expenses associated with administrative services and business operations, such as personnel, office space, equipment, and advertising. Vanguard also provides marketing services to the funds. Although shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (or in the case of a fund with multiple share classes, each share class of the fund) pays its allocated share of The Vanguard Group's marketing costs. -------------------------------------------------------------------------------- PLAIN TALK ABOUT VANGUARD'S UNIQUE CORPORATE STRUCTURE The Vanguard Group is truly a mutual mutual fund company. It is owned jointly by the funds it oversees and thus indirectly by the shareholders in those funds. Most other mutual funds are operated by management companies that may be owned by one person, by a private group of individuals, or by public investors who own the management company's stock. The management fees charged by these companies include a profit component over and above the companies' cost of providing services. By contrast, Vanguard provides services to its member funds on an at-cost basis, with no profit component, which helps to keep the funds' expenses low. -------------------------------------------------------------------------------- Investment Advisor The Vanguard Group, Inc. (Vanguard), P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Fixed Income Group. As of December 31, 2008, Vanguard served as advisor for approximately $xxx billion in assets. Vanguard manages the Fund on an at-cost basis, subject to the supervision and oversight of the trustees and officers of the Fund. For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the semiannual report to shareholders covering the fiscal period ended June 30, 2009, which will be available 60 days after that date. George U. Sauter, Chief Investment Officer and Managing Director of Vanguard. As Chief Investment Officer, he is responsible for the oversight of Vanguard's Quantitative Equity and Fixed Income Groups. The investments managed by these two groups include active quantitative equity funds, equity index funds, active bond funds, index bond funds, stable value portfolios, and money market funds. Since joining Vanguard in 1987, Mr. Sauter has been a key contributor to the development 13 of Vanguard's stock indexing and active quantitative equity investment strategies. He received his A.B. in Economics from Dartmouth College and an M.B.A. in Finance from the University of Chicago. Robert F. Auwaerter, Principal of Vanguard and head of Vanguard's Fixed Income Group. He has direct oversight responsibility for all money market funds, bond funds, and stable value portfolios managed by the Fixed Income Group. He has managed investment portfolios since 1978 and has been with Vanguard since 1981. He received his B.S. in Finance from The Wharton School of the University of Pennsylvania and an M.B.A. from Northwestern University. The managers primarily responsible for the day-to-day management of the Fund are: Kenneth E. Volpert, CFA, Principal of Vanguard and head of Vanguard's Taxable Bond Group. He has managed investment portfolios since 1982; has been with Vanguard since 1992; and has co-managed the Fund since 2009. Education: B.S., University of Illinois; M.B.A., University of Chicago. Gregory Davis, CFA, Principal of Vanguard, head of Vanguard's Bond Index Group, and Portfolio Manager for Vanguard. He has worked in investment management for Vanguard since 1999; has managed investment portfolios since 2000; and has co-managed the Fund since 2009. Education: B.S., Pennsylvania State University; M.B.A.,The Wharton School of the University of Pennsylvania. The Statement of Additional Information provides information about each portfolio manager's compensation, other accounts under management, and ownership of securities in the Fund. Dividends, Capital Gains, and Taxes Fund Distributions The Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net capital gains realized from the sale of its holdings. The Fund's income dividends accrue daily and are distributed on the first business day of every month; capital gains distributions generally occur annually in December. In addition, the Fund may occasionally make supplemental distributions at some other time during the year. You can receive distributions of income or capital gains in cash, or you can have them automatically reinvested in more shares of the Fund. 14 -------------------------------------------------------------------------------- PLAIN TALK ABOUT DISTRIBUTIONS As a shareholder, you are entitled to your portion of a fund's income from interest as well as capital gains from the fund's sale of investments. Income consists of interest the fund earns from its money market and bond investments. Capital gains are realized whenever the fund sells securities for higher prices than it paid for them. These capital gains are either short-term or long-term, depending on whether the fund held the securities for one year or less or for more than one year. -------------------------------------------------------------------------------- Basic Tax Points Vanguard will send you a statement each year showing the tax status of all your distributions. In addition, investors in taxable accounts should be aware of the following basic federal income tax points: . Distributions are taxable to you whether or not you reinvest these amounts in additional Fund shares. . Distributions declared in December--if paid to you by the end of January--are taxable as if received in December. . Any dividend and short-term capital gains distributions that you receive are taxable to you as ordinary income. . Any distributions of net long-term capital gains are taxable to you as long-term capital gains, no matter how long you've owned shares in the Fund. . Capital gains distributions may vary considerably from year to year as a result of the Fund's normal investment activities and cash flows. . A sale or exchange of Fund shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return. Dividend and capital gains distributions that you receive, as well as your gains or losses from any sale or exchange of Fund shares, may be subject to state and local income taxes. Depending on your state's rules, however, any dividends attributable to interest earned on direct obligations of the U.S. government may be exempt from state and local taxes. Vanguard will notify you each year how much, if any, of your dividends may qualify for this exemption. General Information Backup withholding. By law, Vanguard must withhold 28% of any taxable distributions or redemptions from your account if you do not: . Provide us with your correct taxpayer identification number; . Certify that the taxpayer identification number is correct; and 15 . Confirm that you are not subject to backup withholding. Similarly, Vanguard must withhold taxes from your account if the IRS instructs us to do so. Foreign investors. Vanguard funds generally are not sold outside the United States, except to certain qualified investors. If you reside outside the United States, please consult our website at www.vanguard.com and review "Non-U.S. investors." Foreign investors should be aware that U.S. withholding and estate taxes may apply to any investments in Vanguard funds. Invalid addresses. If a dividend or capital gains distribution check mailed to your address of record is returned as undeliverable, Vanguard will automatically reinvest all future distributions until you provide us with a valid mailing address. Tax consequences. This prospectus provides general tax information only. If you are investing through a tax-deferred retirement account, such as an IRA, special tax rules apply. Please consult your tax advisor for detailed information about a fund's tax consequences for you. Share Price Share price, also known as net asset value (NAV), is calculated each business day as of the close of regular trading on the New York Stock Exchange, generally 4 p.m., Eastern time. Each share class has its own NAV, which is computed by dividing the total assets, minus liabilities, allocated to each share class by the number of Fund shares outstanding for that class. On holidays or other days when the Exchange is closed, the NAV is not calculated, and the Fund does not transact purchase or redemption requests. Debt securities held by a Vanguard fund are valued based on information furnished by an independent pricing service or market quotations. Certain short-term debt instruments used to manage a fund's cash are valued on the basis of amortized cost. The values of any mutual fund shares held by a fund are based on the NAVs of the shares. The values of any ETF or closed-end fund shares held by a fund are based on the market value of the shares. When the fund determines that pricing-service information or market quotations either are not readily available or do not accurately reflect the value of a security, the security is priced at its fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security). A fund also may use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day). Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities 16 used by a fund to calculate the NAV may differ from quoted or published prices for the same securities. Vanguard fund share prices can be found daily in the mutual fund listings of most major newspapers under various "Vanguard" headings. INVESTING WITH VANGUARD Vanguard Total Bond Market II Index Fund has been established by Vanguard as an investment vehicle for the Vanguard Target Retirement and Vanguard LifeStrategy Funds as well as certain trusts and accounts managed by Vanguard or its affiliates. The Fund is not available to other investors. Vanguard reserves the right to change the availability of the Fund or offer additional Funds at any time without prior notice to shareholders. Purchases, redemptions, and exchanges of shares issued by Vanguard Total Bond Market II Index Fund are conducted by Vanguard or its affiliates on behalf of the participating funds, trusts, and accounts. In all cases, transactions will be based on the Fund's next-determined NAV after Vanguard receives the request (or, in the case of new contributions, the next-determined NAV after Vanguard receives the order). As long as this request is received before the close of trading on the New York Stock Exchange, generally 4 p.m., Eastern time, the investor will receive that day's NAV. This is known as the trade date. Transaction requests received after that time receive a trade date of the first business day following the date of receipt. The trade date may vary, depending on the method of payment for the transaction. Portfolio Holdings We generally post on our website at www.vanguard.com, in the Holdings section of the Fund's Profile page, a detailed list of the securities held by the Fund (under Portfolio Holdings), as of the most recent calendar-quarter-end. This list is generally updated within 30 days after the end of each calendar quarter. Vanguard may exclude any portion of these portfolio holdings from publication when deemed in the best interest of the Fund. Please consult the Fund's Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund's portfolio holdings. CFA/(R)/ is a trademark owned by CFA Institute. Standard & Poor's/(R)/,S&P/(R)/, S&P 500/(R)/, Standard & Poor's 500, and 500 are trademarks of The McGraw-Hill Companies, Inc., and have been licensed for use by The Vanguard Group, Inc. Vanguard mutual funds are not sponsored, endorsed, sold, or promoted by Standard & Poor's, and Standard & Poor's makes no representation regarding the advisability of investing in the funds. 17 GLOSSARY OF INVESTMENT TERMS Active Management. An investment approach that seeks to exceed the average returns of the financial markets. Active managers rely on research, market forecasts, and their own judgment and experience in selecting securities to buy and sell. Bond. A debt security (IOU) issued by a corporation, government, or government agency in exchange for the money you lend it. In most instances, the issuer agrees to pay back the loan by a specific date and make regular interest payments until that date. Capital Gains Distribution. Payment to mutual fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses. Corporate Bond. An IOU issued by a business that wants to borrow money. As with other types of bonds, the issuer promises to repay the borrowed money on a specific date and to make interest payments in the meantime. Coupon. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security. Dividend Distribution. Payment to mutual fund shareholders of income from interest or dividends generated by a fund's investments. Expense Ratio. The percentage of a fund's average net assets used to pay its expenses during a fiscal year. The expense ratio includes management expenses--such as advisory fees, account maintenance, reporting, accounting, legal, and other administrative expenses--and any 12b-1 distribution fees. It does not include the transaction costs of buying and selling portfolio securities. Face Value. The amount to be paid at a bond's maturity; also known as the par value or principal. Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower must pay a fixed, variable, or floating rate of interest. Inception Date. The date on which the assets of a fund (or one of its share classes) are first invested in accordance with the fund's investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is measured from the inception date. International Dollar-Denominated Bond. A bond denominated in U.S. dollars issued by foreign governments and companies. Because the bond's value is designated in dollars, an investor is not exposed to foreign-currency risk. 18 Investment-Grade Bond. A debt security whose credit quality is considered by independent bond-rating agencies, or through independent analysis conducted by a fund's advisor, to be sufficient to ensure timely payment of principal and interest under current economic circumstances. Debt securities rated in one of the four highest rating categories are considered "investment-grade." Other debt securities may be considered by the advisor to be investment-grade. Mortgage-Backed Security. A bond or pass-through certificate that represents an interest in an underlying pool of mortgages and is issued by various government agencies or private corporations. Unlike ordinary fixed income securities, mortgage-backed securities include both interest and principal as part of their regular payments. Passive Management. A low-cost investment strategy in which a mutual fund attempts to track--rather than outperform--a specified market benchmark or "index"; also known as indexing. Securities. Stocks, bonds, money market instruments, and other investment vehicles. Total Return. A percentage change, over a specified time period, in a mutual fund's net asset value, assuming the reinvestment of all distributions of dividends and capital gains. Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund's volatility, the wider the fluctuations in its returns. Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment's price. 19 This page intentionally left blank. This page intentionally left blank. [SHIP LOGO VANGUARD /(R)/] Institutional Division P.O. Box 2900 Valley Forge, PA 19482-2900 CONNECT WITH VANGUARD/(R)/ > www.vanguard.com For More Information If you would like more information about Vanguard Total Bond Market Index II Fund, the following documents are available free upon request: Annual/Semiannual Reports to Shareholders Additional information about the Fund's investments will be available in the Fund's annual and semiannual reports to shareholders. In the annual report, you will find a discussion of the market conditions and investment strategies that significantly affected the Fund's performance during its last fiscal year. Statement of Additional Information (SAI) The SAI provides more detailed information about the Fund. The SAI is incorporated by reference into (and is thus legally a part of) this prospectus. To receive a free copy of the latest annual or semiannual report (once available) or the SAI, or to request additional information about the Fund or other Vanguard funds, please visit www.vanguard.com or contact us as follows: If you are an individual investor: The Vanguard Group Investor Information Department P.O. Box 2900 Valley Forge, PA 19482-2900 Telephone: 800-662-7447 (SHIP); Text telephone for people with hearing impairment: 800-952-3335 If you are a client of Vanguard's Institutional Division: The Vanguard Group Institutional Investor Information Department P.O. Box 2900 Valley Forge, PA 19482-2900 Telephone: 888-809-8102; Text telephone for people with hearing impairment: 800-952-3335 If you are a current Vanguard shareholder and would like information about your account, account transactions, and/or account statements, please call: Client Services Department Telephone: 800-662-2739 (CREW); Text telephone for people with hearing impairment: 800-749-7273 Information Provided by the Securities and Exchange Commission (SEC) You can review and copy information about the Fund (including the SAI) at the SEC's Public Reference Room in Washington, DC. To find out more about this public service, call the SEC at 202-551-8090. Reports and other information about the Fund are also available in the EDGAR database on the SEC's Internet site at www.sec.gov, or you can receive copies of this information, for a fee, by electronic request at the following e-mail address: publicinfo@sec.gov, or by writing the Public Reference Section, Securities and Exchange Commission, Washington, DC 20549-0102. Fund's Investment Company Act file number: 811-4681 (C) 2009 The Vanguard Group, Inc. All rights reserved. Vanguard Marketing Corporation, Distributor. I635 012009 Information contained in this Statement of Additional Information is subject to completion or amendment. A registration statement for Vanguard Total Bond Market II Index Fund has been filed with the U.S. Securities and Exchange Commission but has not yet become effective. Shares of Vanguard Total Bond Market II Index Fund may not be sold, nor may offers to buy be accepted, prior to the time the registration statement becomes effective. This Statement of Additional Information is not a prospectus. PART B VANGUARD/(R)/ BOND INDEX FUNDS (THE TRUST) VANGUARD TOTAL BOND MARKET II INDEX (THE FUND) STATEMENT OF ADDITIONAL INFORMATION JANUARY XX, 2009 This Statement of Additional Information is not a prospectus but should be read in conjunction with the Fund's current prospectus, Vanguard Total Bond Market II Index Fund, dated January xx, 2009. To obtain, without charge, the prospectus or the most recent Annual Report to Shareholders, which contains the Fund's financial statements as hereby incorporated by reference, please contact Vanguard. PHONE: INVESTOR INFORMATION DEPARTMENT AT 800-662-7447; ONLINE: WWW.VANGUARD.COM TABLE OF CONTENTS DESCRIPTION OF THE TRUST..............................................B-1 INVESTMENT POLICIES...................................................B-3 INVESTMENT LIMITATIONS................................................B-21 SHARE PRICE...........................................................B-22 PURCHASE AND REDEMPTION OF SHARES.....................................B-22 MANAGEMENT OF THE FUNDS...............................................B-23 INVESTMENT ADVISORY SERVICES..........................................B-34 PORTFOLIO TRANSACTIONS................................................B-35 PROXY VOTING GUIDELINES...............................................B-36 FINANCIAL STATEMENTS..................................................B-40 DESCRIPTION OF BOND RATINGS...........................................B-40 DESCRIPTION OF THE TRUST ORGANIZATION Vanguard Bond Index Funds (the Trust) was organized as a Maryland corporation in 1986 and was reorganized as a Delaware statutory trust in May 1998. Prior to its reorganization as a Delaware statutory trust, the Trust was known as Vanguard Bond Index Fund, Inc. The Trust is registered with the United States Securities and Exchange Commission (the SEC) under the Investment Company Act of 1940 (the 1940 Act) as an open-end, diversified management investment company. The Trust currently offers the following funds (and classes thereof):

SHARECLASSES/1/ -------------- FUND/2/ INVESTOR ADMIRAL SIGNAL INSTITUTIONAL ETF ------ -------- ------- ------ ------------- --- Vanguard Total Bond Market Index Fund Yes Yes Yes No Yes Vanguard Total Bond Market II Index Fund Yes No No Yes No Vanguard Short-Term Bond Index Fund Yes Yes Yes No Yes Vanguard Intermediate-Term Bond Index Fund Yes Yes Yes Yes Yes Vanguard Long-Term Bond Index Fund Yes No No Yes Yes Vanguard Inflation-Protected Securities Fund/3/ Yes Yes No Yes No 1 Individually a class; collectively the classes. 2 Individually, a Fund; collectively, the Funds. 3 Prior to November 13, 2007, the Fund was a series of Vanguard Fixed Income Securities Funds.

B-1 This Statement of Additional Information relates only to Vanguard Total Bond Market II Index Fund. A separate Statement of Additional Information (dated April 25, 2008), which relates to Vanguard Inflation Protected Securities Fund, Total Bond Market Index Fund, Intermediate-Term Bond Index Fund, Long-Term Bond Index Fund, and Short-Term Bond Index Fund, can be obtained free of charge by contacting Vanguard at 800-662-7447. The Trust has the ability to offer additional funds or classes of shares. There is no limit on the number of full and fractional shares that may be issued for a single fund or class of shares. The Fund described in this Statement of Additional Information is a member fund. There are two types of Vanguard funds, member funds and non-member funds. Member funds jointly own The Vanguard Group, Inc. (Vanguard), contribute to Vanguard's capital, and receive services at cost from Vanguard pursuant to a Funds' Service Agreement. Non-member funds do not contribute to Vanguard's capital, but they do receive services pursuant to special services agreements. See "Management of the Fund" for more information. SERVICE PROVIDERS CUSTODIAN.[To Be Determined], serves as the Fund's custodian. The custodian is responsible for maintaining the Fund's assets, keeping all necessary accounts and records of Fund assets, and appointing any foreign sub-custodians or foreign securities depositories. INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM. PricewaterhouseCoopers LLP, Two Commerce Square, Suite 1700, 2001 Market Street, Philadelphia, PA 19103-7042, serves as the Fund's independent registered public accounting firm. The independent registered public accounting firm audits the Fund's annual financial statements and provides other related services. TRANSFER AND DIVIDEND-PAYING AGENT. The Fund's transfer agent and dividend-paying agent is Vanguard, P.O. Box 2600, Valley Forge, PA 19482. CHARACTERISTICS OF THE FUND'S SHARES RESTRICTIONS ON HOLDING OR DISPOSING OF SHARES. There are no restrictions on the right of shareholders to retain or dispose of the Fund's shares, other than those described in the Fund's current prospectus and elsewhere in this Statement of Additional Information or the possible future termination of the Fund or a share class. The Fund and each share class may be terminated by reorganization into another mutual fund or class or by liquidation and distribution of the assets of the Fund or class. Unless terminated by reorganization or liquidation, the Fund and each share class will continue indefinitely. SHAREHOLDER LIABILITY. The Trust is organized under Delaware law, which provides that shareholders of a statutory trust are entitled to the same limitations of personal liability as shareholders of a corporation organized under Delaware law. This means that a shareholder of the Fund generally will not be personally liable for payment of the Fund's debts. Some state courts, however, may not apply Delaware law on this point. We believe that the possibility of such a situation arising is remote. DIVIDEND RIGHTS. The shareholders of each class of the Fund are entitled to receive any dividends or other distributions declared by the Fund for each such class. No shares of the Fund have priority or preference over any other shares of the Fund with respect to distributions. Distributions will be made from the assets of the Fund and will be paid ratably to all shareholders of a particular class according to the number of shares of the class held by shareholders on the record date. The amount of dividends per share may vary between separate share classes of the Fund based upon differences in the net asset values of the different classes and differences in the way that expenses are allocated between share classes pursuant to a multiple class plan. VOTING RIGHTS. Shareholders are entitled to vote on a matter if: (1) the matter concerns an amendment to the Declaration of Trust that would adversely affect to a material degree the rights and preferences of the shares of the Fund or any class; (2) the trustees determine that it is necessary or desirable to obtain a shareholder vote; (3) a merger or consolidation, share conversion, share exchange, or sale of assets is proposed and a shareholder vote is required by the 1940 Act to approve the transaction; or (4) a shareholder vote is required under the 1940 Act. The 1940 Act requires a shareholder vote under various circumstances, including to elect or remove trustees upon the written request of shareholders representing 10% or more of the Fund's net assets, to change any fundamental policy of the Fund and to B-2 enter into certain merger transactions. Unless otherwise required by applicable law, shareholders of the Fund receive one vote for each dollar of net asset value owned on the record date, and a fractional vote for each fractional dollar of net asset value owned on the record date. However, only the shares of the Fund or class affected by a particular matter are entitled to vote on that matter. In addition, each class has exclusive voting rights on any matter submitted to shareholders that relates solely to that class, and each class has separate voting rights on any matter submitted to shareholders in which the interests of one class differ from the interests of another. Voting rights are noncumulative and cannot be modified without a majority vote. LIQUIDATION RIGHTS. In the event that the Fund is liquidated, shareholders will be entitled to receive a pro rata share of the Fund's net assets. In the event that a class of shares is liquidated, shareholders of that class will be entitled to receive a pro rata share of the Fund's net assets that are allocated to that class. Shareholders may receive cash, securities, or a combination of the two. PREEMPTIVE RIGHTS. There are no preemptive rights associated with the Fund's shares. CONVERSION RIGHTS. Shareholders of the Fund may convert their shares into another class of shares of the same Fund upon the satisfaction of any then applicable eligibility requirements as described in the Fund's current prospectus. REDEMPTION PROVISIONS. The Fund's redemption provisions are described in its current prospectus and elsewhere in this Statement of Additional Information. SINKING FUND PROVISIONS. The Fund has no sinking fund provisions. CALLS OR ASSESSMENT. The Fund's shares, when issued, are fully paid and non-assessable. TAX STATUS OF THE FUND The Fund expects to qualify each year as a "regulated investment company" under Subchapter M of the Internal Revenue Code of 1986, as amended (the IRC). This special tax status means that the Fund will not be liable for federal tax on income and capital gains distributed to shareholders. In order to preserve its tax status, the Fund must comply with certain requirements. If the Fund fails to meet these requirements in any taxable year, it will be subject to tax on its taxable income at corporate rates, and all distributions from earnings and profits, including any distributions of net tax-exempt income and net long-term capital gains, will be taxable to shareholders as ordinary income. In addition, the Fund could be required to recognize unrealized gains, pay substantial taxes and interest, and make substantial distributions before regaining its tax status as a regulated investment company. INVESTMENT POLICIES Some of the investment policies described below and in the Fund's prospectus set forth percentage limitations on the Fund's investment in, or holdings of, certain securities or other assets. Unless otherwise required by law, compliance with these policies will be determined immediately after the acquisition of such securities or assets. Subsequent changes in values, net assets, or other circumstances will not be considered when determining whether the investment complies with the Fund's investment policies and limitations. The following policies and explanations supplement the Fund's investment objective and policies set forth in the prospectus. With respect to the different investments discussed below, the Fund may acquire such investments to the extent consistent with its investment objective and policies. 80% POLICY. Under normal circumstances, the Total Bond Market II Index Fund invests at least 80% of its assets in bonds that are part of its target index. In applying the 80% policy, the Fund's assets include its net assets and borrowings for investment purposes. ASSET-BACKED SECURITIES. Asset-backed securities are securities that represent a participation in, or are secured by and payable from, pools of underlying assets such as debt securities, bank loans, motor vehicle installment sales contracts, installment loan contracts, leases of various types of real and personal property, receivables from revolving credit (i.e., credit card) agreements, and other categories of receivables. These underlying assets are securitized through the use of trusts and special purpose entities. Payment of interest and repayment of principal on asset-backed securities may be largely dependent upon the cash flows generated by the underlying assets backing the securities and, in certain cases, may be supported by letters of credit, surety bonds, or other credit enhancements. The rate of principal payments on asset-backed securities is related to the rate of principal payments, including prepayments, on the underlying assets. B-3 The credit quality of asset-backed securities depends primarily on the quality of the underlying assets, the level of credit support, if any, provided for the securities, and the credit quality of the credit-support provider, if any. The value of asset-backed securities may be affected by the various factors described above and other factors, such as changes in interest rates, the availability of information concerning the pool and its structure, the creditworthiness of the servicing agent for the pool, the originator of the underlying assets, or the entities providing the credit enhancement. Asset-backed securities are often subject to more rapid repayment than their stated maturity date would indicate, as a result of the pass-through of prepayments of principal on the underlying assets. Prepayments of principal by borrowers or foreclosure or other enforcement action by creditors shorten the term of the underlying assets. The occurrence of prepayments is a function of several factors, such as the level of interest rates, general economic conditions, the location and age of the underlying obligations, and other social and demographic conditions. A fund's ability to maintain positions in asset-backed securities is affected by the reductions in the principal amount of the underlying assets because of prepayments. A fund's ability to reinvest prepayments of principal (as well as interest and other distributions and sale proceeds) at a comparable yield is subject to generally prevailing interest rates at that time. The value of asset-backed securities varies with changes in market interest rates generally and the differentials in yields among various kinds of U.S. government securities, mortgage-backed securities, and asset-backed securities. In periods of rising interest rates, the rate of prepayment tends to decrease, thereby lengthening the average life of the underlying securities. Conversely, in periods of falling interest rates, the rate of prepayment tends to increase, thereby shortening the average life of such assets. Because prepayments of principal generally occur when interest rates are declining, an investor, such as a fund, generally has to reinvest the proceeds of such prepayments at lower interest rates than those at which the assets were previously invested. Therefore, asset-backed securities have less potential for capital appreciation in periods of falling interest rates than other income-bearing securities of comparable maturity. Because asset-backed securities generally do not have the benefit of a security interest in the underlying assets that is comparable to a mortgage, asset-backed securities present certain additional risks that are not present with mortgage-backed securities. For example, revolving credit receivables are generally unsecured and the debtors on such receivables are entitled to the protection of a number of state and federal consumer credit laws, many of which give debtors the right to set-off certain amounts owed, thereby reducing the balance due. Automobile receivables generally are secured, but by automobiles, rather than by real property. Most issuers of automobile receivables permit loan servicers to retain possession of the underlying assets. If the servicer of a pool of underlying assets sells them to another party, there is the risk that the purchaser could acquire an interest superior to that of holders of the asset-backed securities. In addition, because of the large number of vehicles involved in a typical issue of asset-backed securities and technical requirements under state law, the trustee for the holders of the automobile receivables may not have a proper security interest in the automobiles. Therefore, there is the possibility that recoveries on repossessed collateral may not be available to support payments on these securities. BORROWING. A fund's ability to borrow money is limited by its investment policies and limitations, by the 1940 Act, and by applicable exemptions, no-action letters, interpretations, and other pronouncements issued from time to time by the SEC and its staff or any other regulatory authority with jurisdiction. Under the 1940 Act, a fund is required to maintain continuous asset coverage (that is, total assets including borrowings, less liabilities exclusive of borrowings) of 300% of the amount borrowed, with an exception for borrowings not in excess of 5% of the fund's total assets made for temporary or emergency purposes. Any borrowings for temporary purposes in excess of 5% of the fund's total assets must maintain continuous asset coverage. If the 300% asset coverage should decline as a result of market fluctuations or for other reasons, a fund may be required to sell some of its portfolio holdings within three days (excluding Sundays and holidays) to reduce the debt and restore the 300% asset coverage, even though it may be disadvantageous from an investment standpoint to sell securities at that time. Borrowing will tend to exaggerate the effect on net asset value of any increase or decrease in the market value of a fund's portfolio. Money borrowed will be subject to interest costs that may or may not be recovered by earnings on the securities purchased. A fund also may be required to maintain minimum average balances in connection with a borrowing or to pay a commitment or other fee to maintain a line of credit; either of these requirements would increase the cost of borrowing over the stated interest rate. The SEC takes the position that other transactions that have a leveraging effect on the capital structure of a fund or are economically equivalent to borrowing can be viewed as constituting a form of borrowing by the fund for purposes of the 1940 Act. These transactions can include entering into reverse repurchase agreements; engaging in mortgage-dollar-roll transactions; selling securities short (other than short sales "against-the-box"); buying and selling certain derivatives (such B-4 as futures contracts); selling (or writing) put and call options; engaging in sale-buybacks; entering into firm-commitment and standby-commitment agreements; engaging in when-issued, delayed-delivery, or forward-commitment transactions; and other trading practices that have a leveraging effect on the capital structure of a fund or are economically equivalent to borrowing (additional discussion about a number of these transactions can be found below). A borrowing transaction will not be considered to constitute the issuance of a "senior security" by a fund, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund (1) maintains an offsetting financial position; (2) segregates liquid assets (with such liquidity determined by the advisor in accordance with procedures established by the board of trustees) equal (as determined on a daily mark-to-market basis) in value to the fund's potential economic exposure under the borrowing transaction; or (3) otherwise "covers" the transaction in accordance with applicable SEC guidance (collectively, "covers" the transaction). A fund may have to buy or sell a security at a disadvantageous time or price in order to cover a borrowing transaction. In addition, segregated assets may not be available to satisfy redemptions or for other purposes. DEBT SECURITIES. A debt security, sometimes called a fixed income security, is a security consisting of a certificate or other evidence of a debt (secured or unsecured) on which the issuing company or governmental body promises to pay the holder thereof a fixed, variable, or floating rate of interest for a specified length of time, and to repay the debt on the specified maturity date. Some debt securities, such as zero coupon bonds, do not make regular interest payments but are issued at a discount to their principal or maturity value. Debt securities include a variety of fixed income obligations, including, but not limited to, corporate bonds, government securities, municipal securities, convertible securities, mortgage-backed securities, and asset-backed securities. Debt securities include investment-grade securities, non-investment-grade securities, and unrated securities. Debt securities are subject to a variety of risks, such as interest rate risk, income risk, call/prepayment risk, inflation risk, credit risk, and (in the case of foreign securities) country risk and currency risk. The reorganization of an issuer under the federal bankruptcy laws may result in the issuer's debt securities being cancelled without repayment, repaid only in part, or repaid in part or in whole through an exchange thereof for any combination of cash, debt securities, convertible securities, equity securities, or other instruments or rights in respect of the same issuer or a related entity. DEBT SECURITIES -- BANK OBLIGATIONS. Time deposits are non-negotiable deposits maintained in a banking institution for a specified period of time at a stated interest rate. Certificates of deposit are negotiable short-term obligations of commercial banks. Variable rate certificates of deposit are certificates of deposit on which the interest rate is periodically adjusted prior to their stated maturity based upon a specified market rate. As a result of these adjustments, the interest rate on these obligations may be increased or decreased periodically. Frequently, dealers selling variable rate certificates of deposit to a fund will agree to repurchase such instruments, at the fund's option, at par on or near the coupon dates. The dealers' obligations to repurchase these instruments are subject to conditions imposed by various dealers; such conditions typically are the continued credit standing of the issuer and the existence of reasonably orderly market conditions. A fund is also able to sell variable rate certificates of deposit on the secondary market. Variable rate certificates of deposit normally carry a higher interest rate than comparable fixed-rate certificates of deposit. A banker's acceptance is a time draft drawn on a commercial bank by a borrower usually in connection with an international commercial transaction (to finance the import, export, transfer, or storage of goods). The borrower is liable for payment as well as the bank, which unconditionally guarantees to pay the draft at its face amount on the maturity date. Most acceptances have maturities of six months or less and are traded in the secondary markets prior to maturity. DEBT SECURITIES -- COMMERCIAL PAPER. Commercial paper refers to short-term, unsecured promissory notes issued by corporations to finance short-term credit needs, is usually sold on a discount basis, and has a maturity at the time of issuance not exceeding nine months. Commercial paper rated A-1 by Standard & Poor's has the following characteristics: (1) liquidity ratios are adequate to meet cash requirements; (2) long-term senior debt is rated "A" or better; (3) the issuer has access to at least two additional channels of borrowing; (4) basic earnings and cash flow have an upward trend with allowance made for unusual circumstances; (5) typically, the issuer's industry is well established and the issuer has a strong position within the industry; and (6) the reliability and quality of management are unquestioned. Relative strength or weakness of the above factors determines whether the issuer's commercial paper is A-1, A-2, or A-3. The rating Prime-1 is the highest commercial paper rating assigned by Moody's. Among the factors considered by Moody's in assigning ratings are the following: (1) evaluation of the management of the issuer; (2) economic evaluation of the issuer's industry or industries and the appraisal of speculative-type risks that may be inherent in certain areas; (3) evaluation of the issuer's products in relation to competition and customer acceptance; (4) liquidity; (5) amount and quality of long-term debt; (6) trend of earnings over a period of ten years; (7) financial strength of a parent company and B-5 the relationships that exist with the issuer; and (8) recognition by the management of obligations that may be present or may arise as a result of public interest questions and preparations to meet such obligations. Variable amount master demand notes are demand obligations that permit the investment of fluctuating amounts at varying market rates of interest pursuant to arrangement between the issuer and a commercial bank acting as agent for the payees of such notes, whereby both parties have the right to vary the amount of the outstanding indebtedness on the notes. Because variable amount master demand notes are direct lending arrangements between a lender and a borrower, it is not generally contemplated that such instruments will be traded, and there is no secondary market for these notes, although they are redeemable (and thus immediately repayable by the borrower) at face value, plus accrued interest, at any time. In connection with a fund's investment in variable amount master demand notes, Vanguard's investment management staff will monitor, on an ongoing basis, the earning power, cash flow and other liquidity ratios of the issuer, and the borrower's ability to pay principal and interest on demand. DEBT SECURITIES -- INFLATION-INDEXED SECURITIES. Inflation-indexed securities are debt securities the principal value of which is periodically adjusted to reflect the rate of inflation as indicated by the Consumer Price Index (CPI). Inflation-indexed securities may be issued by the U.S. government, agencies and instrumentalities of the U.S. government, and by corporations. Two structures are common. The U.S. Treasury and some other issuers use a structure that accrues inflation into the principal value of the bond. Most other issuers pay out the CPI accruals as part of a semiannual coupon. The periodic adjustment of U.S. inflation-indexed securities is tied to the CPI, which is calculated monthly by the U.S. Bureau of Labor Statistics. The CPI is a measurement of changes in the cost of living, made up of components such as housing, food, transportation, and energy. Inflation-indexed securities issued by a foreign government are generally adjusted to reflect a comparable inflation index, calculated by that government. There can be no assurance that the CPI or any foreign inflation index will accurately measure the real rate of inflation in the prices of goods and services. Moreover, there can be no assurance that the rate of inflation in a foreign country will be correlated to the rate of inflation in the United States. Inflation--a general rise in prices of goods and services--erodes the purchasing power of an investor's portfolio. For example, if an investment provides a "nominal" total return of 5% in a given year and inflation is 2% during that period, the inflation-adjusted, or real, return is 3%. Inflation, as measured by the CPI, has occurred in each of the past 50 years, so investors should be conscious of both the nominal and real returns of their investments. Investors in inflation-indexed securities funds who do not reinvest the portion of the income distribution that is attributable to inflation adjustments will not maintain the purchasing power of the investment over the long term. This is because interest earned depends on the amount of principal invested, and that principal will not grow with inflation if the investor fails to reinvest the principal adjustment paid out as part of a fund's income distributions. While inflation-indexed securities are expected to be protected from long-term inflationary trends, short-term increases in inflation may lead to a decline in value. If interest rates rise due to reasons other than inflation (for example, due to changes in currency exchange rates), investors in these securities may not be protected to the extent that the increase is not reflected in the bond's inflation measure. If the periodic adjustment rate measuring inflation (i.e., the CPI) falls, the principal value of inflation-indexed securities will be adjusted downward, and consequently the interest payable on these securities (calculated with respect to a smaller principal amount) will be reduced. Repayment of the original bond principal upon maturity (as adjusted for inflation) is guaranteed in the case of U.S. Treasury inflation-indexed securities, even during a period of deflation. However, the current market value of the inflation-indexed securities is not guaranteed, and will fluctuate. Other inflation-indexed securities include inflation-related bonds, which may or may not provide a similar guarantee. If a guarantee of principal is not provided, the adjusted principal value of the bond repaid at maturity may be less than the original principal. The value of inflation-indexed securities should change in response to changes in real interest rates. Real interest rates in turn are tied to the relationship between nominal interest rates and the rate of inflation. Therefore, if inflation were to rise at a faster rate than nominal interest rates, real interest rates might decline, leading to an increase in value of inflation-indexed securities. In contrast, if nominal interest rates increased at a faster rate than inflation, real interest rates might rise, leading to a decrease in value of inflation-indexed securities. Any increase in principal for an inflation-indexed security resulting from inflation adjustments is considered by Internal Revenue Service (IRS) regulations to be taxable income in the year it occurs. For direct holders of an inflation-indexed security, this means that taxes must be paid on principal adjustments even though these amounts are not received until the bond matures. By contrast, a fund holding these securities distributes both interest income and the income B-6 attributable to principal adjustments each quarter in the form of cash or reinvested shares (which, like principal adjustments, are taxable to shareholders). DEBT SECURITIES -- NON-INVESTMENT-GRADE SECURITIES. Non-investment-grade securities, also referred to as "high-yield securities" or "junk bonds," are debt securities that are rated lower than the four highest rating categories by a nationally recognized statistical rating organization (for example, lower than Baa3 by Moody's Investors Service, Inc., or lower than BBB- by Standard & Poor's) or are determined to be of comparable quality by the fund's advisor. These securities are generally considered to be, on balance, predominantly speculative with respect to capacity to pay interest and repay principal in accordance with the terms of the obligation and will generally involve more credit risk than securities in the investment-grade categories. Non-investment-grade-securities generally provide greater income and opportunity for capital appreciation than higher quality securities, but they also typically entail greater price volatility and principal and income risk. Analysis of the creditworthiness of issuers of high-yield securities may be more complex than for issuers of investment-grade securities. Thus, reliance on credit ratings in making investment decisions entails greater risks for high-yield securities than for investment-grade debt securities. The success of a fund's advisor in managing high-yield securities is more dependent upon its own credit analysis than is the case with investment-grade securities. Some high-yield securities are issued by smaller, less-seasoned companies, while others are issued as part of a corporate restructuring, such as an acquisition, merger, or leveraged buyout. Companies that issue high-yield securities are often highly leveraged and may not have available to them more traditional methods of financing. Therefore, the risk associated with acquiring the securities of such issuers generally is greater than is the case with investment-grade securities. Some high-yield securities were once rated as investment-grade but have been downgraded to junk bond status because of financial difficulties experienced by their issuers. The market values of high-yield securities tend to reflect individual issuer developments to a greater extent than do investment-grade securities, which in general react to fluctuations in the general level of interest rates. High-yield securities also tend to be more sensitive to economic conditions than are investment-grade securities. A projection of an economic downturn or of a sustained period of rising interest rates, for example, could cause a decline in junk bond prices because the advent of a recession could lessen the ability of a highly leveraged company to make principal and interest payments on its debt securities. If an issuer of high-yield securities defaults, in addition to risking payment of all or a portion of interest and principal, a fund investing in such securities may incur additional expenses to seek recovery. The secondary market on which high-yield securities are traded may be less liquid than the market for investment-grade securities. Less liquidity in the secondary trading market could adversely affect the ability of a fund to sell a high-yield security or the price at which a fund could sell a high-yield security, and could adversely affect the daily net asset value of fund shares. When secondary markets for high-yield securities are less liquid than the market for investment-grade securities, it may be more difficult to value the securities because such valuation may require more research, and elements of judgment may play a greater role in the valuation because there is less reliable, objective data available. Except as otherwise provided in a fund's prospectus, if a credit-rating agency changes the rating of a portfolio security held by a fund, the fund may retain the portfolio security if the advisor deems it in the best interests of shareholders. DEBT SECURITIES -- STRUCTURED AND INDEXED SECURITIES. Structured securities (also called "structured notes") and indexed securities are derivative debt securities, the interest rate or principal of which is determined by an unrelated indicator. Indexed securities include structured notes as well as securities other than debt securities, the interest rate or principal of which is determined by an unrelated indicator. The value of the principal of and/or interest on structured and indexed securities is determined by reference to changes in the value of a specific asset, reference rate, or index (the reference) or the relative change in two or more references. The interest rate or the principal amount payable upon maturity or redemption may be increased or decreased, depending upon changes in the applicable reference. The terms of the structured and indexed securities may provide that in certain circumstances no principal is due at maturity and, therefore, may result in a loss of invested capital. Structured and indexed securities may be positively or negatively indexed, so that appreciation of the reference may produce an increase or a decrease in the interest rate or value of the security at maturity. In addition, changes in the interest rate or the value of the structured or indexed security at maturity may be calculated as a specified multiple of the change in the value of the reference; therefore, the value of such security may be very volatile. Structured and indexed securities may entail a greater degree of market risk than other types of debt securities because the investor bears the risk of the reference. Structured or indexed securities may also B-7 be more volatile, less liquid, and more difficult to accurately price than less complex securities or more traditional debt securities. DEBT SECURITIES -- U.S. GOVERNMENT SECURITIES. The term "U.S. Government Securities" refers to a variety of debt securities that are issued or guaranteed by the U.S. Treasury, by various agencies of the U.S. government, and by various instrumentalities that have been established or sponsored by the U.S. government. The term also refers to repurchase agreements collateralized by such securities. U.S. Treasury securities are backed by the full faith and credit of the U.S. government. Other types of securities issued or guaranteed by Federal agencies and U.S. government-sponsored instrumentalities may or may not be backed by the full faith and credit of the U.S. government. The U.S. government, however, does not guarantee the market price of any U.S. government securities. In the case of securities not backed by the full faith and credit of the U.S. government, the investor must look principally to the agency or instrumentality issuing or guaranteeing the obligation for ultimate repayment, and may not be able to assert a claim against the United States itself in the event the agency or instrumentality does not meet its commitment. Some of the U.S. government agencies that issue or guarantee securities include the Government National Mortgage Association, the Export-Import Bank of the United States, the Farmers Home Administration, the Federal Housing Administration, the Maritime Administration, the Small Business Administration, and the Tennessee Valley Authority. An instrumentality of the U.S. government is a government agency organized under Federal charter with government supervision. Instrumentalities issuing or guaranteeing securities include, among others, the Federal Home Loan Banks and the Federal National Mortgage Association. DEBT SECURITIES -- VARIABLE AND FLOATING RATE SECURITIES. Variable and floating rate securities are debt securities that provide for periodic adjustments in the interest rate paid on the security. Variable rate securities provide for a specified periodic adjustment in the interest rate, while floating rate securities have interest rates that change whenever there is a change in a designated benchmark rate or the issuer's credit quality. There is a risk that the current interest rate on variable and floating rate securities may not accurately reflect current market interest rates or adequately compensate the holder for the current creditworthiness of the issuer. Some variable or floating rate securities are structured with liquidity features such as (1) put options or tender options that permit holders (sometimes subject to conditions) to demand payment of the unpaid principal balance plus accrued interest from the issuers or certain financial intermediaries or (2) auction rate features, remarketing provisions, or other maturity-shortening devices designed to enable the issuer to refinance or redeem outstanding debt securities (market-dependent liquidity features). Variable or floating rate securities that include market-dependent liquidity features may have greater liquidity risk than other securities, due to (for example) the failure of a market-dependent liquidity feature to operate as intended (as a result of the issuer's declining creditworthiness, adverse market conditions, or other factors) or the inability or unwillingness of a participating broker-dealer to make a secondary market for such securities. As a result, variable or floating rate securities that include market-dependent liquidity features may lose value and the holders of such securities may be required to retain them until the later of the repurchase date, the resale date, or maturity. A demand instrument with a demand notice exceeding seven days may be considered illiquid if there is no secondary market for such security. DEBT SECURITIES -- ZERO-COUPON AND PAY-IN-KIND SECURITIES. Zero-coupon and pay-in-kind securities are debt securities that do not make regular cash interest payments. Zero-coupon securities generally do not pay interest. Pay-in-kind securities pay interest through the issuance of additional securities. These securities are generally issued at a discount to their principal or maturity value. Because such securities do not pay current cash income, the price of these securities can be volatile when interest rates fluctuate. Although these securities do not pay current cash income, federal income tax law requires the holders of zero-coupon and pay-in-kind securities to include in income each year the portion of the original issue discount and other non-cash income on such securities accrued during that year. Each fund that holds such securities intends to pass along such interest as a component of the fund's distributions of net investment income. DERIVATIVES. A derivative is a financial instrument that has a value that is based on--or "derived from"--the values of other assets, reference rates, or indexes. Derivatives may relate to a wide variety of underlying references, such as commodities, stocks, bonds, interest rates, currency exchange rates, and related indexes. Derivatives include futures contracts and options on futures contracts, forward-commitment transactions, options on securities, caps, floors, collars, swap agreements, and other financial instruments. Some derivatives, such as futures contracts and certain options, are traded on U.S. commodity and securities exchanges, while other derivatives, such as swap agreements, are privately negotiated and entered into in the over-the-counter (OTC) market. The risks associated with the use of derivatives are B-8 different from, and possibly greater than, the risks associated with investing directly in the securities, assets, or market indexes on which the derivatives are based. Derivatives are used by some investors for speculative purposes. Derivatives also may be used for a variety of purposes that do not constitute speculation, such as hedging, risk management, seeking to stay fully invested, seeking to reduce transaction costs, seeking to simulate an investment in equity or debt securities or other investments, seeking to add value by using derivatives to more efficiently implement portfolio positions when derivatives are favorably priced relative to equity or debt securities or other investments, and for other purposes. There is no assurance that any derivatives strategy used by a fund's advisor will succeed. The counterparties to the funds' derivatives will not be considered the issuers thereof for purposes of certain provisions of the 1940 Act and the IRC, although such derivatives may qualify as securities or investments under such laws. The funds' advisors, however, will monitor and adjust, as appropriate, the funds' credit risk exposure to derivative counterparties. Derivative products are highly specialized instruments that require investment techniques and risk analyses different from those associated with stocks, bonds, and other traditional investments. The use of a derivative requires an understanding not only of the underlying instrument but also of the derivative itself, without the benefit of observing the performance of the derivative under all possible market conditions. The use of derivatives generally involves the risk that a loss may be sustained as a result of the insolvency or bankruptcy of the other party to the contract (usually referred to as a "counterparty") or the failure of the counterparty to make required payments or otherwise comply with the terms of the contract. Additionally, the use of credit derivatives can result in losses if a fund's advisor does not correctly evaluate the creditworthiness of the issuer on which the credit derivative is based. Derivatives may be subject to liquidity risk, which exists when a particular derivative is difficult to purchase or sell. If a derivative transaction is particularly large or if the relevant market is illiquid (as is the case with many OTC derivatives), it may not be possible to initiate a transaction or liquidate a position at an advantageous time or price. Derivatives may be subject to pricing or "basis" risk, which exists when a particular derivative becomes extraordinarily expensive relative to historical prices or the prices of corresponding cash market instruments. Under certain market conditions, it may not be economically feasible to initiate a transaction or liquidate a position in time to avoid a loss or take advantage of an opportunity. Because many derivatives have a leverage component, adverse changes in the value or level of the underlying asset, reference rate, or index can result in a loss substantially greater than the amount invested in the derivative itself. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. A derivative transaction will not be considered to constitute the issuance of a "senior security" by a fund, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund covers the transaction in accordance with the requirements described under the heading "Borrowing." Like most other investments, derivative instruments are subject to the risk that the market value of the instrument will change in a way detrimental to a fund's interest. A fund bears the risk that its advisor will incorrectly forecast future market trends or the values of assets, reference rates, indexes, or other financial or economic factors in establishing derivative positions for the fund. If the advisor attempts to use a derivative as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the derivative will have or will develop imperfect or no correlation with the portfolio investment. This could cause substantial losses for the fund. Although hedging strategies involving derivative instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments. Many derivatives, in particular OTC derivatives, are complex and often valued subjectively. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a fund. EXCHANGE-TRADED FUNDS. A fund may purchase shares of exchange-traded funds (ETFs), including ETF shares issued by other Vanguard funds. Typically, a fund would purchase ETF shares for the same reason it would purchase (and as an alternative to purchasing) futures contracts: to obtain exposure to all or a portion of the stock or bond market. ETF shares enjoy several advantages over futures. Depending on the market, the holding period, and other factors, ETF shares can be less costly and more tax-efficient than futures. In addition, ETF shares can be purchased for smaller sums, offer exposure to market sectors and styles for which there is no suitable or liquid futures contract, and do not involve leverage. An investment in an ETF generally presents the same primary risks as an investment in a conventional fund (i.e., one that is not exchange traded) that has the same investment objective, strategies, and policies. The price of an ETF can fluctuate within a wide range, and a fund could lose money investing in an ETF if the prices of the securities owned by the ETF go down. In addition, ETFs are subject to the following risks that do not apply to conventional funds: (1) the B-9 market price of the ETF's shares may trade at a discount to their net asset value; (2) an active trading market for an ETF's shares may not develop or be maintained; or (3) trading of an ETF's shares may be halted if the listing exchange's officials deem such action appropriate, the shares are de-listed from the exchange, or the activation of market-wide "circuit breakers" (which are tied to large decreases in stock prices) halts stock trading generally. Most ETFs are investment companies. Therefore, a fund's purchases of ETF shares generally are subject to the limitations on, and the risks of, a fund's investments in other investment companies, which are described under the heading "Other Investment Companies." Vanguard ETF(TM) *Shares are exchange-traded shares that represent an interest in an investment portfolio held by Vanguard funds. A fund's investments in Vanguard ETF Shares are also generally subject to the descriptions, limitations, and risks described under the heading "Other Investment Companies, "except as provided by an exemption granted by the SEC that permits registered investment companies to invest in a Vanguard fund that issues ETF Shares beyond the limits of Section 12(d)(1) of the 1940 Act, subject to certain terms and conditions. --------- * U.S. Pat. No. 6,879,964 B2; 7,337,138. FUTURES CONTRACTS AND OPTIONS ON FUTURES CONTRACTS. Futures contracts and options on futures contracts are derivatives. A futures contract is a standardized agreement between two parties to buy or sell at a specific time in the future a specific quantity of a commodity at a specific price. The commodity may consist of an asset, a reference rate, or an index. A security futures contract relates to the sale of a specific quantity of shares of a single equity security or a narrow-based securities index. The value of a futures contract tends to increase and decrease in tandem with the value of the underlying commodity. The buyer of a futures contract enters into an agreement to purchase the underlying commodity on the settlement date and is said to be "long" the contract. The seller of a futures contract enters into an agreement to sell the underlying commodity on the settlement date and is said to be "short" the contract. The price at which a futures contract is entered into is established either in the electronic marketplace or by open outcry on the floor of an exchange between exchange members acting as traders or brokers. Open futures contracts can be liquidated or closed out by physical delivery of the underlying commodity or payment of the cash settlement amount on the settlement date, depending on the terms of the particular contract. Some financial futures contracts (such as security futures) provide for physical settlement at maturity. Other financial futures contracts (such as those relating to interest rates, foreign currencies, and broad-based securities indexes) generally provide for cash settlement at maturity. In the case of cash settled futures contracts, the cash settlement amount is equal to the difference between the final settlement price on the last trading day of the contract and the price at which the contract was entered into. Most futures contracts, however, are not held until maturity but instead are "offset" before the settlement date through the establishment of an opposite and equal futures position. The purchaser or seller of a futures contract is not required to deliver or pay for the underlying commodity unless the contract is held until the settlement date. However, both the purchaser and seller are required to deposit "initial margin" with a futures commission merchant (FCM) when the futures contract is entered into. Initial margin deposits are typically calculated as a percentage of the contract's market value. If the value of either party's position declines, that party will be required to make additional "variation margin" payments to settle the change in value on a daily basis. This process is known as "marking-to-market." A futures transaction will not be considered to constitute the issuance of a "senior security" by a fund for purposes of the 1940 Act, and such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund covers the transaction in accordance with the requirements described under the heading "Borrowing." An option on a futures contract (or futures option) conveys the right, but not the obligation, to purchase (in the case of a call option) or sell (in the case of a put option) a specific futures contract at a specific price (called the "exercise" or "strike" price) any time before the option expires. The seller of an option is called an option writer. The purchase price of an option is called the premium. The potential loss to an option buyer is limited to the amount of the premium plus transaction costs. This will be the case, for example, if the option is held and not exercised prior to its expiration date. Generally, an option writer sells options with the goal of obtaining the premium paid by the option buyer. If an option sold by an option writer expires without being exercised, the writer retains the full amount of the premium. The option writer, however, has unlimited economic risk because its potential loss, except to the extent offset by the premium received when the option was written, is equal to the amount the option is "in-the-money" at the expiration date. A call option is in-the-money if the value of the underlying futures contract exceeds the exercise price of the option. A put option is in-- B-10 the-money if the exercise price of the option exceeds the value of the underlying futures contract. Generally, any profit realized by an option buyer represents a loss for the option writer. A fund that takes the position of a writer of a futures option is required to deposit and maintain initial and variation margin with respect to the option, as described above in the case of futures contracts. A futures option transaction will not be considered to constitute the issuance of a "senior security" by a fund for purposes of the 1940 Act, and such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund covers the transaction in accordance with the requirements described under the heading "Borrowing." Each fund intends to comply with Rule 4.5 of the Commodity Futures Trading Commission, under which a mutual fund is conditionally excluded from the definition of the term "commodity pool operator." A fund will only enter into futures contracts and futures options that are standardized and traded on a U.S. or foreign exchange, board of trade, or similar entity, or quoted on an automated quotation system. FUTURES CONTRACTS AND OPTIONS ON FUTURES CONTRACTS -- RISKS. The risk of loss in trading futures contracts and in writing futures options can be substantial, because of the low margin deposits required, the extremely high degree of leverage involved in futures and options pricing, and the potential high volatility of the futures markets. As a result, a relatively small price movement in a futures position may result in immediate and substantial loss (or gain) to the investor. For example, if at the time of purchase, 10% of the value of the futures contract is deposited as margin, a subsequent 10% decrease in the value of the futures contract would result in a total loss of the margin deposit, before any deduction for the transaction costs, if the account were then closed out. A 15% decrease would result in a loss equal to 150% of the original margin deposit if the contract were closed out. Thus, a purchase or sale of a futures contract, and the writing of a futures option, may result in losses in excess of the amount invested in the position. In the event of adverse price movements, a fund would continue to be required to make daily cash payments to maintain its required margin. In such situations, if the fund has insufficient cash, it may have to sell portfolio securities to meet daily margin requirements (and segregation requirements, if applicable) at a time when it may be disadvantageous to do so. In addition, on the settlement date, a fund may be required to make delivery of the instruments underlying the futures positions it holds. A fund could suffer losses if it is unable to close out a futures contract or a futures option because of an illiquid secondary market. Futures contracts and futures options may be closed out only on an exchange that provides a secondary market for such products. However, there can be no assurance that a liquid secondary market will exist for any particular futures product at any specific time. Thus, it may not be possible to close a futures or option position. Moreover, most futures exchanges limit the amount of fluctuation permitted in futures contract prices during a single trading day. The daily limit establishes the maximum amount that the price of a futures contract may vary either up or down from the previous day's settlement price at the end of a trading session. Once the daily limit has been reached in a particular type of contract, no trades may be made on that day at a price beyond that limit. The daily limit governs only price movement during a particular trading day and therefore does not limit potential losses, because the limit may prevent the liquidation of unfavorable positions. Futures contract prices have occasionally moved to the daily limit for several consecutive trading days with little or no trading, thereby preventing prompt liquidation of future positions and subjecting some futures traders to substantial losses. The inability to close futures and options positions also could have an adverse impact on the ability to hedge a portfolio investment or to establish a substitute for a portfolio investment. Treasury futures are generally not subject to such daily limits. A fund bears the risk that its advisor will incorrectly predict future market trends. If the advisor attempts to use a futures contract or a futures option as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the futures position will have or will develop imperfect or no correlation with the portfolio investment. This could cause substantial losses for the fund. Although hedging strategies involving futures products can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments. A fund could lose margin payments it has deposited with its FCM, if, for example, the FCM breaches its agreement with the fund or becomes insolvent or goes into bankruptcy. In that event, the fund may be entitled to return of margin owed to it only in proportion to the amount received by the FCM's other customers, potentially resulting in losses to the fund. HYBRID INSTRUMENT. A hybrid instrument, or hybrid, is an interest in an issuer that combines the characteristics of an equity security, a debt security, a commodity, and/or a derivative. A hybrid may have characteristics that, on the whole, B-11 more strongly suggest the existence of a bond, stock or other traditional investment, but may also have prominent features that are normally associated with a different type of investment. Moreover, hybrid instruments may be treated as a particular type of investment for one regulatory purpose (such as taxation) and may be simultaneously treated as a different type of investment for a different regulatory purpose (such as securities or commodity regulation). Hybrids can be used as an efficient means of pursuing a variety of investment goals, including increased total return, duration management, and currency hedging. Because hybrids combine features of two or more traditional investments, and may involve the use of innovative structures, hybrids present risks that may be similar to, different from, or greater than those associated with traditional investments with similar characteristics. Examples of hybrid instruments include convertible securities, which combine the investment characteristics of bonds and common stocks, and perpetual bonds, which are structured like fixed income securities, have no maturity date, and may be characterized as debt or equity for certain regulatory purposes. Another example of a hybrid is a commodity-linked bond, such as a bond issued by an oil company that pays a small base level of interest with additional interest that accrues in correlation to the extent to which oil prices exceed a certain predetermined level. Such a hybrid would be a combination of a bond and a call option on oil. In the case of hybrids that are structured like fixed income securities (such as structured notes), the principal amount or interest rate is generally tied (positively or negatively) to the price of some commodity, currency, securities index, interest rate, or other economic factor (each a benchmark). For some hybrids, the principal amount payable at maturity or interest rate may be increased or decreased, depending on changes in the value of the benchmark. Other hybrids do not bear interest or pay dividends. The value of a hybrid or its interest rate may be a multiple of a benchmark and, as a result, may be leveraged and move (up or down) more steeply and rapidly than the benchmark. These benchmarks may be sensitive to economic and political events, such as commodity shortages and currency devaluations, which cannot be readily foreseen by the purchaser of a hybrid. Under certain conditions, the redemption value of a hybrid could be zero. Thus, an investment in a hybrid may entail significant market risks that are not associated with a similar investment in a traditional, U.S. dollar-denominated bond with a fixed principal amount that pays a fixed rate or floating rate of interest. The purchase of hybrids also exposes a fund to the credit risk of the issuer of the hybrids. Depending on the level of a fund's investment in hybrids, these risks may cause significant fluctuations in the fund's net asset value. Certain issuers of hybrid instruments known as structured products may be deemed to be investment companies as defined in the 1940 Act. As a result, the funds' investments in these products may be subject to limits described under the heading "Other Investment Companies." INTERFUND BORROWING AND LENDING. The SEC has granted an exemption permitting the Vanguard funds to participate in Vanguard's interfund lending program. This program allows the Vanguard funds to borrow money from and lend money to each other for temporary or emergency purposes. The program is subject to a number of conditions, including, among other things, the requirement that: (1) no fund may borrow or lend money through the program unless it receives a more favorable interest rate than is typically available from a bank for a comparable transaction; (2) no equity, taxable bond, or money market fund may loan money if the loan would cause its aggregate outstanding loans through the program to exceed 5%, 7.5%, or 10%, respectively, of its net assets at the time of the loan; and (3) a fund's interfund loans to any one fund shall not exceed 5% of the lending fund's net assets. In addition, a Vanguard fund may participate in the program only if and to the extent that such participation is consistent with the fund's investment objective and investment policies. The boards of trustees of the Vanguard funds are responsible for overseeing the interfund lending program. Any delay in repayment to a lending fund could result in a lost investment opportunity or additional borrowing costs. LOAN INTERESTS AND DIRECT DEBT INSTRUMENTS. Loan interests and direct debt instruments are interests in amounts owed by a corporate, governmental, or other borrower to lenders or lending syndicates (in the case of loans and loan participations), to suppliers of goods or services (in the case of trade claims or other receivables), or to other parties. These investments involve a risk of loss in case of the default, insolvency, or bankruptcy of the borrower and may offer less legal protection to the purchaser in the event of fraud or misrepresentation, or there may be a requirement that a purchaser supply additional cash to a borrower on demand. Purchasers of loans and other forms of direct indebtedness depend primarily upon the creditworthiness of the borrower for payment of interest and repayment of principal. If scheduled interest or principal payments are not made, or are not made in a timely manner, the value of the instrument may be adversely affected. Loans that are fully secured provide more protections than unsecured loans in the event of failure to make scheduled interest or principal payments. However, there is no assurance that the liquidation of collateral from a secured loan would satisfy the borrower's B-12 obligation, or that the collateral could be liquidated. Indebtedness of borrowers whose creditworthiness is poor involves substantially greater risks and may be highly speculative. Borrowers that are in bankruptcy or restructuring may never pay off their indebtedness, or may pay only a small fraction of the amount owed. Direct indebtedness of developing countries also involves a risk that the governmental entities responsible for the repayment of the debt may be unable, or unwilling, to pay interest and repay principal when due. Investments in loans through direct assignment of a financial institution's interests with respect to a loan may involve additional risks. For example, if a loan is foreclosed, the purchaser could become part owner of any collateral, and would bear the costs and liabilities associated with owning and disposing of the collateral. In addition, it is at least conceivable that under emerging legal theories of lender liability, a purchaser could be held liable as a co-lender. Direct debt instruments may also involve a risk of insolvency of the lending bank or other intermediary. A loan is often administered by a bank or other financial institution that acts as agent for all holders. The agent administers the terms of the loan, as specified in the loan agreement. Unless the purchaser has direct recourse against the borrower, the purchaser may have to rely on the agent to apply appropriate credit remedies against a borrower under the terms of the loan or other indebtedness. If assets held by the agent for the benefit of a purchaser were determined to be subject to the claims of the agent's general creditors, the purchaser might incur certain costs and delays in realizing payment on the loan or loan participation and could suffer a loss of principal or interest. Direct indebtedness may include letters of credit, revolving credit facilities, or other standby financing commitments that obligate purchasers to make additional cash payments on demand. These commitments may have the effect of requiring a purchaser to increase its investment in a borrower at a time when it would not otherwise have done so, even if the borrower's condition makes it unlikely that the amount will ever be repaid. A fund's investment policies will govern the amount of total assets that it may invest in any one issuer or in issuers within the same industry. For purposes of these limitations, a fund generally will treat the borrower as the "issuer" of indebtedness held by the fund. In the case of loan participations where a bank or other lending institution serves as financial intermediary between a fund and the borrower, if the participation does not shift to the fund the direct debtor-creditor relationship with the borrower, SEC interpretations require the fund, in some circumstances, to treat both the lending bank or other lending institution and the borrower as "issuers" for purposes of the fund's investment policies. Treating a financial intermediary as an issuer of indebtedness may restrict a fund's ability to invest in indebtedness related to a single financial intermediary, or a group of intermediaries engaged in the same industry, even if the underlying borrowers represent many different companies and industries. MORTGAGE DOLLAR ROLLS. A mortgage dollar roll is a transaction in which a fund sells a mortgage-backed security to a dealer and simultaneously agrees to repurchase a similar security (but not the same security) in the future at a pre-determined price. A mortgage-dollar-roll program may be structured to simulate an investment in mortgage-backed securities at a potentially lower cost, or with potentially reduced administrative burdens, than directly holding mortgage-backed securities. A mortgage dollar roll can be viewed, like a reverse repurchase agreement, as a collateralized borrowing in which a fund pledges a mortgage-backed security to a dealer to obtain cash. Unlike the dealer of reverse repurchase agreements, the dealer with which a fund enters into a mortgage-dollar-roll transaction is not obligated to return the same securities as those originally sold by the fund, but rather only securities that are "substantially identical." To be considered substantially identical, the securities returned to a fund generally must: (1) be collateralized by the same types of underlying mortgages; (2) be issued by the same agency and be part of the same program; (3) have similar original stated maturities; (4) have identical net coupon rates; (5) have similar market yields (and therefore prices); and (6) satisfy "good delivery" requirements, meaning that the aggregate principal amounts of the securities delivered and received back must be within a certain percentage of the initial amount delivered. A mortgage dollar roll may be considered to constitute a borrowing transaction. A mortgage-dollar-roll transaction will not be considered to constitute the issuance of a "senior security" by a fund for purposes of the 1940 Act, and such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund covers the transaction in accordance with the requirements described under the heading "Borrowing." Mortgage dollar rolls will be used only if consistent with a fund's investment objective and strategies and will not be used to leverage a fund's assets or change its risk profile. The proceeds of mortgage-dollar-roll transactions will be invested in high-quality, short-term fixed income securities. MORTGAGE-BACKED SECURITIES. Mortgage-backed securities are securities that represent direct or indirect participation in, or are collateralized by and payable from, mortgage loans secured by real property or instruments derived from such B-13 loans. Mortgage-backed securities include various types of securities such as government stripped mortgage-backed securities, adjustable rate mortgage-backed securities, and collateralized mortgage obligations. Generally, mortgage-backed securities represent interests in pools of mortgage loans assembled for sale to investors by various governmental agencies, such as the Government National Mortgage Association (GNMA), by government-related organizations, such as the Federal National Mortgage Association (FNMA) and the Federal Home Loan Mortgage Corporation (FHLMC), as well as by private issuers, such as commercial banks, savings and loan institutions, and mortgage bankers. The average maturity of pass-through pools of mortgage-backed securities in which a fund may invest varies with the maturities of the underlying mortgage instruments. In addition, a pool's average maturity may be shortened by unscheduled payments on the underlying mortgages. Factors affecting mortgage prepayments include the level of interest rates, general economic and social conditions, the location of the mortgaged property, and the age of the mortgage. Because prepayment rates of individual mortgage pools vary widely, the average life of a particular pool cannot be predicted accurately. Mortgage-backed securities may be classified as private, government, or government-related, depending on the issuer or guarantor. Private mortgage-backed securities represent interest in pass-through pools consisting principally of conventional residential mortgage loans created by non-government issuers, such as commercial banks and savings and loan associations and private mortgage insurance companies. Government mortgage-backed securities are backed by the full faith and credit of the U.S. government. GNMA, the principal U.S. guarantor of these securities, is a wholly-owned U.S. government corporation within the Department of Housing and Urban Development. Government-related mortgage-backed securities are not backed by the full faith and credit of the U.S. government. Issuers include FNMA and FHLMC, which are congressionally chartered corporations. In September 2008, the U.S. Treasury placed FNMA and FHLMC under conservatorship and appointed the Federal Housing Finance Agency (FHFA) to manage their daily operations. In addition, the U.S. Treasury entered into purchase agreements with FNMA and FHLMC to provide them with capital in exchange for senior preferred stock. Pass-through securities issued by FNMA are guaranteed as to timely payment of principal and interest by FNMA. Participation certificates representing interests in mortgages from FHLMC's national portfolio are guaranteed as to the timely payment of interest and principal by FHLMC. Private, government, or government-related entities may create mortgage loan pools offering pass-through investments in addition to those described above. The mortgages underlying these securities may be alternative mortgage instruments, that is, mortgage instruments whose principal or interest payments may vary or whose terms to maturity may be shorter than customary. Mortgage-backed securities are often subject to more rapid repayment than their stated maturity date would indicate as a result of the pass-through of prepayments of principal on the underlying loans. Prepayments of principal by mortgagors or mortgage foreclosures shorten the term of the mortgage pool underlying the mortgage-backed security. A fund's ability to maintain positions in mortgage-backed securities is affected by the reductions in the principal amount of such securities resulting from prepayments. A fund's ability to reinvest prepayments of principal at comparable yield is subject to generally prevailing interest rates at that time. The values of mortgage-backed securities vary with changes in market interest rates generally and the differentials in yields among various kinds of U.S. government securities, mortgage-backed securities, and asset-backed securities. In periods of rising interest rates, the rate of prepayment tends to decrease, thereby lengthening the average life of a pool of mortgages supporting a mortgage-backed security. Conversely, in periods of falling interest rates, the rate of prepayment tends to increase thereby shortening the average life of such a pool. Because prepayments of principal generally occur when interest rates are declining, an investor, such as a fund, generally has to reinvest the proceeds of such prepayments at lower interest rates than those at which its assets were previously invested. Therefore, mortgage-backed securities have less potential for capital appreciation in periods of falling interest rates than other income-bearing securities of comparable maturity. MORTGAGE-BACKED SECURITIES -- ADJUSTABLE RATE MORTGAGE-BACKED SECURITIES. Adjustable rate mortgage-backed securities (ARMBSs) have interest rates that reset at periodic intervals. Acquiring ARMBSs permits a fund to participate in increases in prevailing current interest rates through periodic adjustments in the coupons of mortgages underlying the pool on which ARMBSs are based. Such ARMBSs generally have higher current yield and lower price fluctuations than is the case with more traditional fixed income debt securities of comparable rating and maturity. In addition, when prepayments of principal are made on the underlying mortgages during periods of rising interest rates, a fund can reinvest the proceeds of such prepayments at rates higher than those at which they were previously invested. Mortgages underlying most ARMBSs, however, have limits on the allowable annual or lifetime increases that can be made in the interest rate that the mortgagor pays. Therefore, if current interest rates rise above such limits over the period of the limitation, a fund holding an ARMBS does not benefit from further increases in interest rates. Moreover, B-14 when interest rates are in excess of coupon rates (i.e., the rates being paid by mortgagors) of the mortgages, ARMBSs behave more like fixed income securities and less like adjustable rate securities and are subject to the risks associated with fixed income securities. In addition, during periods of rising interest rates, increases in the coupon rate of adjustable rate mortgages generally lag current market interest rates slightly, thereby creating the potential for capital depreciation on such securities. MORTGAGE-BACKED SECURITIES -- COLLATERALIZED MORTGAGE OBLIGATIONS. Collateralized mortgage obligations (CMOs) are mortgage-backed securities that are collateralized by whole loan mortgages or mortgage pass-through securities. The bonds issued in a CMO transaction are divided into groups, and each group of bonds is referred to as a "tranche." Under the traditional CMO structure, the cash flows generated by the mortgages or mortgage pass-through securities in the collateral pool are used to first pay interest and then pay principal to the CMO bondholders. The bonds issued under a traditional CMO structure are retired sequentially as opposed to the pro-rata return of principal found in traditional pass-through obligations. Subject to the various provisions of individual CMO issues, the cash flow generated by the underlying collateral (to the extent it exceeds the amount required to pay the stated interest) is used to retire the bonds. Under a CMO structure, the repayment of principal among the different tranches is prioritized in accordance with the terms of the particular CMO issuance. The "fastest-pay" tranches of bonds, as specified in the prospectus for the issuance, would initially receive all principal payments. When those tranches of bonds are retired, the next tranche, or tranches, in the sequence, as specified in the prospectus, receive all of the principal payments until they are retired. The sequential retirement of bond groups continues until the last tranche is retired. Accordingly, the CMO structure allows the issuer to use cash flows of long maturity, monthly-pay collateral to formulate securities with short, intermediate, and long final maturities and expected average lives and risk characteristics. In recent years, new types of CMO tranches have evolved. These include floating rate CMOs, planned amortization classes, accrual bonds, and CMO residuals. These newer structures affect the amount and timing of principal and interest received by each tranche from the underlying collateral. Under certain of these new structures, given classes of CMOs have priority over others with respect to the receipt of prepayments on the mortgages. Therefore, depending on the type of CMOs in which a fund invests, the investment may be subject to a greater or lesser risk of prepayment than other types of mortgage-backed securities. The primary risk of CMOs is the uncertainty of the timing of cash flows that results from the rate of prepayments on the underlying mortgages serving as collateral and from the structure of the particular CMO transaction (that is, the priority of the individual tranches). An increase or decrease in prepayment rates (resulting from a decrease or increase in mortgage interest rates) will affect the yield, average life, and price of CMOs. The prices of certain CMOs, depending on their structure and the rate of prepayments, can be volatile. Some CMOs may also not be as liquid as other securities. MORTGAGE-BACKED SECURITIES--HYBRID ARMS. A hybrid adjustable-rate mortgage (hybrid ARM) is a type of mortgage in which the interest rate is fixed for a specified period and then resets periodically, or floats, for the remaining mortgage term. Hybrid ARMs are usually referred to by their fixed and floating periods. For example, a 5/1 ARM refers to a mortgage with a 5-year fixed interest rate period, followed by a 1-year interest rate adjustment period. During the initial interest period (i.e., the initial five years for a 5/1 hybrid ARM), hybrid ARMs behave more like fixed income securities and are subject to the risks associated with fixed income securities. All hybrid ARMs have reset dates. A reset date is the date when a hybrid ARM changes from a fixed interest rate to a floating interest rate. At the reset date, a hybrid ARM can adjust by a maximum specified amount based on a margin over an identified index. Like ARMBSs, hybrid ARMs have periodic and lifetime limitations on the increases that can be made to the interest rates that mortgagors pay. Therefore, if during a floating rate period interest rates rise above the interest rate limits of the hybrid ARM, a fund holding the hybrid ARM does not benefit from further increases in interest rates. MORTGAGE-BACKED SECURITIES -- STRIPPED MORTGAGE-BACKED SECURITIES. Stripped mortgage-backed securities (SMBSs) are derivative multi-class mortgage-backed securities. SMBSs may be issued by agencies or instrumentalities of the U.S. government, or by private originators of, or investors in, mortgage loans, including savings and loan associations, mortgage banks, commercial banks, investment banks, and special purpose entities formed or sponsored by any of the foregoing. SMBSs are usually structured with two classes that receive different proportions of the interest and principal distributions on a pool of mortgage assets. A common type of SMBS will have one class receiving some of the interest and most of the principal from the mortgage assets, while the other class will receive most of the interest and the remainder of the principal. In the most extreme case, one class will receive all of the interest (the "IO" class), while the B-15 other class will receive all of the principal (the principal-only or "PO" class). The price and yield-to-maturity on an IO class is extremely sensitive to the rate of principal payments (including prepayments) on the related underlying mortgage assets, and a rapid rate of principal payments may have a material adverse effect on a fund's yield to maturity from these securities. If the underlying mortgage assets experience greater than anticipated prepayments of principal, a fund may fail to recoup some or all of its initial investment in these securities, even if the security is in one of the highest rating categories. Although SMBSs are purchased and sold by institutional investors through several investment banking firms acting as brokers or dealers, these securities were only recently developed. As a result, established trading markets have not yet developed and, accordingly, these securities may be deemed "illiquid" and subject to a fund's limitations on investment in illiquid securities. OPTIONS. An option is a derivative. An option on a security (or index) is a contract that gives the holder of the option, in return for the payment of a "premium," the right, but not the obligation, to buy from (in the case of a call option) or sell to (in the case of a put option) the writer of the option the security underlying the option (or the cash value of the index) at a specified exercise price prior to the expiration date of the option. The writer of an option on a security has the obligation upon exercise of the option (1) to deliver the underlying security upon payment of the exercise price (in the case of a call option) or (2) to pay the exercise price upon delivery of the underlying security (in the case of a put option). The writer of an option on an index has the obligation upon exercise of the option to pay an amount equal to the cash value of the index minus the exercise price, multiplied by the specified multiplier for the index option. The multiplier for an index option determines the size of the investment position the option represents. Unlike exchange-traded options, which are standardized with respect to the underlying instrument, expiration date, contract size, and strike price, the terms of OTC options (options not traded on exchanges) generally are established through negotiation with the other party to the option contract. While this type of arrangement allows the purchaser or writer greater flexibility to tailor an option to its needs, OTC options generally involve greater credit risk than exchange-traded options, which are guaranteed by the clearing organization of the exchanges where they are traded. The buyer (or holder) of an option is said to be "long" the option, while the seller (or writer) of an option is said to be "short" the option. A call option grants to the holder the right to buy (and obligates the writer to sell) the underlying security at the strike price. A put option grants to the holder the right to sell (and obligates the writer to buy) the underlying security at the strike price. The purchase price of an option is called the "premium." The potential loss to an option buyer is limited to the amount of the premium plus transaction costs. This will be the case if the option is held and not exercised prior to its expiration date. Generally, an option writer sells options with the goal of obtaining the premium paid by the option buyer, but that person could also seek to profit from an anticipated rise or decline in option prices. If an option sold by an option writer expires without being exercised, the writer retains the full amount of the premium. The option writer, however, has unlimited economic risk because its potential loss, except to the extent offset by the premium received when the option was written, is equal to the amount the option is "in-the-money" at the expiration date. A call option is in-the-money if the value of the underlying position exceeds the exercise price of the option. A put option is in-the-money if the exercise price of the option exceeds the value of the underlying position. Generally, any profit realized by an option buyer represents a loss for the option writer. The writing of an option will not be considered to constitute the issuance of a "senior security" by a fund for purposes of the 1940 Act, and such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund covers the transaction in accordance with the requirements described under the heading "Borrowing." If a trading market in particular options were to become unavailable, investors in those options (such as the funds) would be unable to close out their positions until trading resumes, and they may be faced with substantial losses if the value of the underlying interest moves adversely during that time. Even if the market were to remain available, there may be times when options prices will not maintain their customary or anticipated relationships to the prices of the underlying interests and related interests. Lack of investor interest, changes in volatility, or other factors or conditions might adversely affect the liquidity, efficiency, continuity, or even the orderliness of the market for particular options. A fund bears the risk that its advisor will not accurately predict future market trends. If the advisor attempts to use an option as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the option will have or will develop imperfect or no correlation with the portfolio investment. This could cause substantial losses for the fund. Although hedging strategies involving options can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments. Many B-16 options, in particular OTC options, are complex and often valued based on subjective factors. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a fund. OTHER INVESTMENT COMPANIES. A fund may invest in other investment companies to the extent permitted by applicable law or SEC exemption. Under Section 12(d)(1) of the 1940 Act, a fund generally may invest up to 10% of its assets in shares of investment companies and up to 5% of its assets in any one investment company, as long as no investment represents more than 3% of the voting stock of an acquired investment company. In addition, no funds for which Vanguard acts as an advisor may, in the aggregate, own more than 10% of the voting stock of a closed-end investment company. The 1940 Act and related rules provide certain exemptions from these restrictions. If a fund invests in other investment companies, shareholders will bear not only their proportionate share of the fund's expenses (including operating expenses and the fees of the advisor), but also, indirectly, the similar expenses of the underlying investment companies. Shareholders would also be exposed to the risks associated not only to the investments of the fund but also to the portfolio investments of the underlying investment companies. Certain types of investment companies, such as closed-end investment companies, issue a fixed number of shares that typically trade on a stock exchange or over-the-counter at a premium or discount to their net asset value. Others are continuously offered at net asset value but also may be traded on the secondary market. REPURCHASE AGREEMENTS. A repurchase agreement is an agreement under which a fund acquires a fixed income security (generally a security issued by the U.S. government or an agency thereof, a banker's acceptance, or a certificate of deposit) from a commercial bank, broker, or dealer, and simultaneously agrees to resell such security to the seller at an agreed upon price and date (normally, the next business day). Because the security purchased constitutes collateral for the repurchase obligation, a repurchase agreement may be considered a loan that is collateralized by the security purchased. The resale price reflects an agreed upon interest rate effective for the period the instrument is held by a fund and is unrelated to the interest rate on the underlying instrument. In these transactions, the securities acquired by a fund (including accrued interest earned thereon) must have a total value in excess of the value of the repurchase agreement and be held by a custodian bank until repurchased. In addition, the investment advisor will monitor a fund's repurchase agreement transactions generally and will evaluate the creditworthiness of any bank, broker, or dealer party to a repurchase agreement relating to a fund. The aggregate amount of any such agreements is not limited except to the extent required by law. The use of repurchase agreements involves certain risks. One risk is the seller's ability to pay the agreed-upon repurchase price on the repurchase date. If the seller defaults, the fund may incur costs in disposing of the collateral, which would reduce the amount realized thereon. If the seller seeks relief under the bankruptcy laws, the disposition of the collateral may be delayed or limited. For example, if the other party to the agreement becomes insolvent and subject to liquidation or reorganization under the bankruptcy or other laws, a court may determine that the underlying security is collateral for a loan by the fund not within its control and therefore the realization by the fund on such collateral may be automatically stayed. Finally, it is possible that the fund may not be able to substantiate its interest in the underlying security and may be deemed an unsecured creditor of the other party to the agreement. RESTRICTED AND ILLIQUID SECURITIES. Illiquid securities are securities that cannot be sold or disposed of in the ordinary course of business within seven business days at approximately the value at which they are being carried on a fund's books. Illiquid securities may include a wide variety of investments, such as: (1) repurchase agreements maturing in more than seven days (unless the agreements have demand/redemption features); (2) OTC options contracts and certain other derivatives (including certain swap agreements); (3) fixed time deposits that are not subject to prepayment or do not provide for withdrawal penalties upon prepayment (other than overnight deposits); (4) participation interests in loans; (5) municipal lease obligations; (6) commercial paper issued pursuant to Section 4(2) of the Securities Act of 1933 (the 1933 Act); and (7) securities whose disposition is restricted under the federal securities laws. Illiquid securities include restricted, privately placed securities that, under the federal securities laws, generally may be resold only to qualified institutional buyers. If a substantial market develops for a restricted security (or other illiquid investment) held by a fund, it may be treated as a liquid security, in accordance with procedures and guidelines approved by the board of trustees. This generally includes securities that are unregistered, that can be sold to qualified institutional buyers in accordance with Rule 144A under the 1933 Act, or that are exempt from registration under the 1933 Act, such as commercial paper. While a fund's advisor monitors the liquidity of restricted securities on a daily basis, the board of trustees oversees and retains ultimate responsibility for the advisor's liquidity determinations. Several factors that the trustees consider in monitoring these decisions include the valuation of a security, the availability of qualified institutional buyers, brokers, and dealers that trade in the security, and the availability of information about the security's issuer. B-17 REVERSE REPURCHASE AGREEMENTS. In a reverse repurchase agreement, a fund sells a security to another party, such as a bank or broker-dealer, in return for cash and agrees to repurchase that security at an agreed-upon price and time. Under a reverse repurchase agreement, the fund continues to receive any principal and interest payments on the underlying security during the term of the agreement. Reverse repurchase agreements involve the risk that the market value of securities retained by the fund may decline below the repurchase price of the securities sold by the fund that it is obligated to repurchase. A reverse repurchase agreement may be considered a borrowing transaction for purposes of the 1940 Act. A reverse repurchase agreement transaction will not be considered to constitute the issuance of a "senior security" by a fund, and such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund covers the transaction in accordance with the requirements described under the heading "Borrowing." A fund will enter into reverse repurchase agreements only with parties whose creditworthiness has been reviewed and found satisfactory by the advisor. SECURITIES LENDING. A fund may lend its investment securities to qualified institutional investors (typically brokers, dealers, banks, or other financial institutions) who may need to borrow securities in order to complete certain transactions, such as covering short sales, avoiding failures to deliver securities, or completing arbitrage operations. By lending its investment securities, a fund attempts to increase its net investment income through the receipt of interest on the securities lent. Any gain or loss in the market price of the securities lent that might occur during the term of the loan would be for the account of the fund. If the borrower defaults on its obligation to return the securities lent because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities lent or in gaining access to the collateral. These delays and costs could be greater for foreign securities. If a fund is not able to recover the securities lent, a fund may sell the collateral and purchase a replacement investment in the market. The value of the collateral could decrease below the value of the replacement investment by the time the replacement investment is purchased. Cash received as collateral through loan transactions may be invested in other eligible securities. Investing this cash subjects that investment to market appreciation or depreciation. The terms and the structure of the loan arrangements, as well as the aggregate amount of securities loans must be consistent with the 1940 Act, and the rules or interpretations of the SEC thereunder. These provisions limit the amount of securities a fund may lend to 33 1/3% of the fund's total assets, and require that (1) the borrower pledge and maintain with the fund collateral consisting of cash, an irrevocable letter of credit, or securities issued or guaranteed by the U.S. government having at all times not less than 100% of the value of the securities lent; (2) the borrower add to such collateral whenever the price of the securities lent rises (i.e., the borrower "marks-to-market" on a daily basis); (3) the loan be made subject to termination by the fund at any time; and (4) the fund receive reasonable interest on the loan (which may include the fund's investing any cash collateral in interest bearing short-term investments), any distribution on the lent securities, and any increase in their market value. Loan arrangements made by each fund will comply with all other applicable regulatory requirements, including the rules of the New York Stock Exchange, which presently require the borrower, after notice, to redeliver the securities within the normal settlement time of three business days. The advisor will consider the creditworthiness of the borrower, among other things, in making decisions with respect to the lending of securities, subject to oversight by the board of trustees. At the present time, the SEC does not object if an investment company pays reasonable negotiated fees in connection with lent securities, so long as such fees are set forth in a written contract and approved by the investment company's trustees. In addition, voting rights pass with the lent securities, but if a fund has knowledge that a material event will occur affecting securities on loan, and in respect of which the holder of the securities will be entitled to vote or consent, the lender must be entitled to call the loaned securities in time to vote or consent. SWAP AGREEMENTS. A swap agreement is a derivative. A swap agreement is an agreement between two parties (counterparties) to exchange payments at specified dates (periodic payment dates) on the basis of a specified amount (notional amount) with the payments calculated with reference to a specified asset, reference rate, or index. Examples of swap agreements include, but are not limited to, interest rate swaps, credit default swaps, equity swaps, commodity swaps, foreign currency swaps, index swaps, and total return swaps. Most swap agreements provide that when the periodic payment dates for both parties are the same, payments are netted, and only the net amount is paid to the counterparty entitled to receive the net payment. Consequently, a fund's current obligations (or rights) under a swap agreement will generally be equal only to the net amount to be paid or received under the agreement, based on the relative values of the positions held by each counterparty. Swap agreements allow for a wide variety of transactions. For example, fixed rate payments may be exchanged for floating rate payments; U.S. dollar-denominated payments may be B-18 exchanged for payments denominated in a different currency; and payments tied to the price of one asset, reference rate, or index may be exchanged for payments tied to the price of another asset, reference rate, or index. An option on a swap agreement, also called a "swaption," is an option that gives the buyer the right, but not the obligation, to enter into a swap on a future date in exchange for paying a market-based "premium." A receiver swaption gives the owner the right to receive the total return of a specified asset, reference rate, or index. A payer swaption gives the owner the right to pay the total return of a specified asset, reference rate, or index. Swaptions also include options that allow an existing swap to be terminated or extended by one of the counterparties. The use of swap agreements by a fund entails certain risks, which may be different from, or possibly greater than, the risks associated with investing directly in the securities and other investments that are the referenced asset for the swap agreement. Swaps are highly specialized instruments that require investment techniques, risk analyses, and tax planning different from those associated with stocks, bonds, and other traditional investments. The use of a swap requires an understanding not only of the referenced asset, reference rate, or index but also of the swap itself, without the benefit of observing the performance of the swap under all possible market conditions. Swap agreements may be subject to liquidity risk, which exists when a particular swap is difficult to purchase or sell. If a swap transaction is particularly large or if the relevant market is illiquid (as is the case with many OTC swaps), it may not be possible to initiate a transaction or liquidate a position at an advantageous time or price, which may result in significant losses. In addition, swap transactions may be subject to a fund's limitation on investments in illiquid securities. Swap agreements may be subject to pricing risk, which exists when a particular swap becomes extraordinarily expensive (or cheap) relative to historical prices or the prices of corresponding cash market instruments. Under certain market conditions, it may not be economically feasible to initiate a transaction or liquidate a position in time to avoid a loss or take advantage of an opportunity or to realize the intrinsic value of the swap agreement. Because some swap agreements have a leverage component, adverse changes in the value or level of the underlying asset, reference rate, or index can result in a loss substantially greater than the amount invested in the swap itself. Certain swaps have the potential for unlimited loss, regardless of the size of the initial investment. A leveraged swap transaction will not be considered to constitute the issuance of a "senior security" by a fund, and such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund covers the transaction in accordance with the requirements described above under the heading "Borrowing." Like most other investments, swap agreements are subject to the risk that the market value of the instrument will change in a way detrimental to a fund's interest. A fund bears the risk that its advisor will not accurately forecast future market trends or the values of assets, reference rates, indexes, or other economic factors in establishing swap positions for the fund. If the advisor attempts to use a swap as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the swap will have or will develop imperfect or no correlation with the portfolio investment. This could cause substantial losses for the fund. Although hedging strategies involving swap instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments. Many swaps, in particular OTC swaps, are complex and often valued subjectively. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a fund. The use of a swap agreement also involves the risk that a loss may be sustained as a result of the insolvency or bankruptcy of the counterparty or the failure of the counterparty to make required payments or otherwise comply with the terms of the agreement. Additionally, the use of credit default swaps can result in losses if a fund's advisor does not correctly evaluate the creditworthiness of the issuer on which the credit swap is based. The swaps market is a relatively new market and is largely unregulated. It is possible that developments in the swaps market, including potential government regulation, could adversely affect a fund's ability to terminate existing swap agreements or to realize amounts to be received under such agreements. TAX MATTERS -- FEDERAL TAX TREATMENT OF FUTURES CONTRACTS. A fund is required for federal income tax purposes to recognize for each taxable year its net unrealized gains and losses on certain futures contracts as of the end of the year as well as those actually realized during the year. In these cases, any gain or loss recognized with respect to a futures contract is considered to be 60% long-term capital gain or loss and 40% short-term capital gain or loss, without regard to the holding period of the contract. Gains and losses on certain other futures contracts (primarily non-U.S. futures contracts) are not recognized until the contracts are closed and are treated as long-term or short-term, depending on the holding period of the contract. Sales of futures contracts that are intended to hedge against a change in the value of B-19 securities held by a fund may affect the holding period of such securities and, consequently, the nature of the gain or loss on such securities upon disposition. A fund may be required to defer the recognition of losses on one position, such as futures contracts, to the extent of any unrecognized gains on a related offsetting position held by the fund. In order for a fund to continue to qualify for federal income tax treatment as a regulated investment company, at least 90% of its gross income for a taxable year must be derived from qualifying income; i.e., dividends, interest, income derived from loans of securities, gains from the sale of securities or of foreign currencies, or other income derived with respect to the fund's business of investing in securities or currencies. It is anticipated that any net gain recognized on futures contracts will be considered qualifying income for purposes of the 90% requirement. A fund will distribute to shareholders annually any net capital gains that have been recognized for federal income tax purposes on futures transactions. Such distributions will be combined with distributions of capital gains realized on the fund's other investments and shareholders will be advised on the nature of the distributions. TAX MATTERS -- FEDERAL TAX TREATMENT OF NON-U.S. TRANSACTIONS. Special rules govern the federal income tax treatment of certain transactions denominated in a currency other than the U.S. dollar or determined by reference to the value of one or more currencies other than the U.S. dollar. The types of transactions covered by the special rules include the following: (1) the acquisition of, or becoming the obligor under, a bond or other debt instrument (including, to the extent provided in Treasury regulations, preferred stock); (2) the accruing of certain trade receivables and payables; and (3) the entering into or acquisition of any forward contract, futures contract, option, or similar financial instrument if such instrument is not marked to market. The disposition of a currency other than the U.S. dollar by a taxpayer whose functional currency is the U.S. dollar is also treated as a transaction subject to the special currency rules. However, foreign currency-related regulated futures contracts and non-equity options are generally not subject to the special currency rules if they are or would be treated as sold for their fair market value at year-end under the marking-to-market rules applicable to other futures contracts unless an election is made to have such currency rules apply. With respect to transactions covered by the special rules, foreign currency gain or loss is calculated separately from any gain or loss on the underlying transaction and is normally taxable as ordinary income or loss. A taxpayer may elect to treat as capital gain or loss foreign currency gain or loss arising from certain identified forward contracts, futures contracts, and options that are capital assets in the hands of the taxpayer and that are not part of a straddle. The Treasury Department issued regulations under which certain transactions subject to the special currency rules that are part of a "section 988 hedging transaction" (as defined in the IRC and the Treasury regulations) will be integrated and treated as a single transaction or otherwise treated consistently for purposes of the IRC. Any gain or loss attributable to the foreign currency component of a transaction engaged in by a fund that is not subject to the special currency rules (such as foreign equity investments other than certain preferred stocks) will be treated as capital gain or loss and will not be segregated from the gain or loss on the underlying transaction. It is anticipated that some of the non-U.S. dollar-denominated investments and foreign currency contracts a fund may make or enter into will be subject to the special currency rules described above. TAX MATTERS -- MARKET DISCOUNT. The price of a bond purchased after its original issuance may reflect market discount that, depending on the particular circumstances, may affect the tax character and amount of income required to be recognized by a fund holding the bond. In determining whether a bond is purchased with market discount, certain de minimis rules apply. TAX MATTERS --TAX CONSIDERATIONS FOR NON-U.S. INVESTORS. U.S. withholding and estate taxes may apply to any investments made by non-U.S. investors in Vanguard funds. The American Jobs Creation Act of 2004 provided relief from U.S. withholding tax for certain properly designated distributions made with respect to a fund's taxable year beginning prior to 2008, assuming the investor provided tax documentation certifying non-U.S. status. The relief does not by its terms apply to a fund's taxable year beginning in or after 2008 unless so extended by Congress. Please be aware that the U.S. tax information contained in this Statement of Additional Information is not intended or written to be used, and cannot be used, for the purpose of avoiding U.S. tax penalties. TEMPORARY INVESTMENTS. A fund may take temporary defensive positions that are inconsistent with the fund's normal fundamental or non-fundamental investment policies and strategies in response to adverse or unusual market, economic, political, or other conditions as determined by the advisor. Such positions could include, but are not limited to, investments in (1) highly liquid short-term fixed income securities issued by or on behalf of municipal or corporate issuers, obligations of the U.S. government and its agencies, commercial paper, and bank certificates of deposit; (2) repurchase agreements involving any such securities; and (3) other money market instruments. There is no limit on B-20 the extent to which the fund may take temporary defensive positions. In taking such positions, the fund may fail to achieve its investment objective. WHEN-ISSUED, DELAYED-DELIVERY, AND FORWARD-COMMITMENT TRANSACTIONS. When-issued, delayed-delivery, and forward-commitment transactions involve a commitment to purchase or sell specific securities at a predetermined price or yield in which payment and delivery take place after the customary settlement period for that type of security. Typically, no interest accrues to the purchaser until the security is delivered. When purchasing securities pursuant to one of these transactions, payment for the securities is not required until the delivery date. However, the purchaser assumes the rights and risks of ownership, including the risks of price and yield fluctuations and the risk that the security will not be issued as anticipated. When a fund has sold a security pursuant to one of these transactions, the fund does not participate in further gains or losses with respect to the security. If the other party to a delayed-delivery transaction fails to deliver or pay for the securities, the fund could miss a favorable price or yield opportunity or suffer a loss. A fund may renegotiate a when-issued or forward-commitment transaction and may sell the underlying securities before delivery, which may result in capital gains or losses for the fund. When-issued, delayed-delivery, and forward-commitment transactions will not be considered to constitute the issuance of a "senior security" by a fund, and such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by the fund, if the fund covers the transaction in accordance with the requirements described under the heading "Borrowing." INVESTMENT LIMITATIONS The Fund is subject to the following fundamental investment limitations, which cannot be changed in any material way without the approval of the holders of a majority of the Fund's shares. For these purposes, a "majority" of shares means shares representing the lesser of: (1) 67% or more of the Fund's net assets voted, so long as shares representing more than 50% of the Fund's net assets are present or represented by proxy; or (2) more than 50% of the Fund's net assets. BORROWING. The Fund may not borrow money in excess of 15% of its net assets, and any borrowings by the Fund must comply with all applicable regulatory requirements. COMMODITIES. The Fund may not invest in commodities, except that it may invest in futures contracts and options transactions. No more than 5% of a Fund's total assets may be used as initial margin deposit for futures contracts, and no more than 20% of the Fund's total assets may be invested in futures contracts or options at any time. DIVERSIFICATION. With respect to 75% of its total assets, the Fund may not: (1) purchase more than 10% of the outstanding voting securities of any one issuer; or (2) purchase securities of any issuer if, as a result, more than 5% of the Fund's total assets would be invested in that issuer's securities. This limitation does not apply to obligations of the U.S. government or its agencies or instrumentalities. ILLIQUID SECURITIES. The Fund may not acquire any security if, as a result, more than 15% of its net assets would be invested in securities that are illiquid. INDUSTRY CONCENTRATION. The Fund will not invest more than 25% of its total assets in any one industry except as necessary to approximate the composition of its target index. INVESTING FOR CONTROL. The Fund may not invest in a company for purposes of controlling its management. INVESTMENT OBJECTIVE. The investment objective of the Fund may not be materially changed without a shareholder vote. LOANS. The Fund may not lend money to any person except by purchasing fixed income securities that are publicly distributed or customarily purchased by institutional investors, by entering into repurchase agreements, by lending its portfolio securities, or through Vanguard's interfund lending program. MARGIN. The Fund may not purchase securities on margin or sell securities short, except as permitted by the Fund's investment policies relating to commodities. OIL, GAS, MINERALS. The Fund may not invest in interests in oil, gas, or other mineral exploration or development programs. PLEDGING ASSETS. The Fund may not pledge, mortgage, or hypothecate more than 15% of its net assets. REAL ESTATE. The Fund may not invest directly in real estate, although it may invest in securities of companies that deal in real estate and bonds secured by real estate. SENIOR SECURITIES. The Fund may not issue senior securities. B-21 UNDERWRITING. The Fund may not act as an underwriter of another issuer's securities, except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act, in connection with the purchase and sale of portfolio securities. Compliance with the investment limitations set forth above is generally measured at the time the securities are purchased. Unless otherwise required by the 1940 Act, if a percentage restriction is adhered to at the time the investment is made, a later change in percentage resulting from a change in the market value of assets will not constitute a violation of such restriction. All investment limitations must comply with applicable regulatory requirements. For more details, see "Investment Policies." None of these limitations prevents the Fund from having an ownership interest in Vanguard. As a part owner of Vanguard, the Fund may own securities issued by Vanguard, make loans to Vanguard, and contribute to Vanguard's costs or other financial requirements. See "Management of the Fund" for more information. SHARE PRICE Multiple-class funds do not have a single share price. Rather, each class has a share price, called its net asset value, or NAV, that is calculated each business day as of the close of regular trading on the New York Stock Exchange (the Exchange), generally 4 p.m., Eastern time. NAV per share is computed by dividing the total assets, minus liabilities, allocated to each share class by the number of Fund shares outstanding for that class. The Exchange typically observes the following holidays: New Year's Day, Martin Luther King, Jr. Day, Presidents' Day (Washington's Birthday), Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day, and Christmas Day. Although the Fund expects the same holidays to be observed in the future, the Exchange may modify its holiday schedule or hours of operation at any time. PURCHASE AND REDEMPTION OF SHARES PURCHASE OF SHARES The purchase price of shares of the Fund is the NAV per share next determined after the purchase request is received in good order, as defined in the Fund's prospectus. REDEMPTION OF SHARES The redemption price of shares of the Fund is the NAV next determined after the redemption request is received in good order, as defined in the Fund's prospectus. The Fund may suspend redemption privileges or postpone the date of payment for redeemed shares: (1) during any period that the Exchange is closed or trading on the Exchange is restricted as determined by the SEC; (2) during any period when an emergency exists, as defined by the SEC, as a result of which it is not reasonably practicable for the Fund to dispose of securities it owns or to fairly determine the value of its assets; and (3) for such other periods as the SEC may permit. The Trust has filed a notice of election with the SEC to pay in cash all redemptions requested by any shareholder of record limited in amount during any 90-day period to the lesser of $250,000 or 1% of the net assets of the Fund at the beginning of such period. If Vanguard determines that it would be detrimental to the best interests of the remaining shareholders of the Fund to make payment wholly or partly in cash, the Fund may pay the redemption price in whole or in part by a distribution in kind of readily marketable securities held by the Fund in lieu of cash in conformity with applicable rules of the SEC. Investors may incur brokerage charges on the sale of such securities received in payment of redemptions. The Fund does not charge redemption fees, except for wire redemptions in amounts less than $5,000 (which will be subject to a charge of $5.00). Shares redeemed may be worth more or less than what was paid for them, depending on the market value of the securities held by the Fund. B-22 RIGHT TO CHANGE POLICIES Vanguard reserves the right to (1) alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, conversion, service, or privilege at any time without prior notice; (2) accept initial purchases by telephone; (3) freeze any account and/or suspend account services if Vanguard has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners, or if we reasonably believe a fraudulent transaction may occur or has occurred; (4) temporarily freeze any account and/or suspend account services upon initial notification to Vanguard of the death of the shareholder until Vanguard receives required documentation in good order; (5) alter, impose, discontinue, or waive any redemption fee, account service fee, or other fees charged to a group of shareholders; and (6) redeem an account or suspend account privileges, without the owner's permission to do so, in cases of threatening conduct or suspicious, fraudulent, or illegal activity. Changes may affect any or all investors. These actions will be taken when, at the sole discretion of Vanguard management, we reasonably believe they are deemed to be in the best interest of a fund. INVESTING WITH VANGUARD THROUGH OTHER FIRMS The Fund has authorized certain agents to accept on its behalf purchase and redemption orders, and those agents are authorized to designate other intermediaries to accept purchase and redemption orders on the Fund's behalf (collectively, Authorized Agents). The Fund will be deemed to have received a purchase or redemption order when an Authorized Agent accepts the order in accordance with the Fund's instructions. In most instances, a customer order that is properly transmitted to an Authorized Agent will be priced at the Fund's NAV next determined after the order is received by the Authorized Agent. MANAGEMENT OF THE FUND VANGUARD The Fund is part of the Vanguard group of investment companies, which consists of more than 150 funds. Through their jointly-owned subsidiary, Vanguard, the Vanguard funds obtain at cost virtually all of their corporate management, administrative, and distribution services. Vanguard also provides investment advisory services on an at-cost basis to several of the Vanguard funds. Vanguard employs a supporting staff of management and administrative personnel needed to provide the requisite services to the funds and also furnishes the funds with necessary office space, furnishings, and equipment. Each fund pays its share of Vanguard's total expenses, which are allocated among the funds under methods approved by the board of trustees of each fund. In addition, each fund bears its own direct expenses, such as legal, auditing, and custodian fees. The funds' officers are also officers and employees of Vanguard. Vanguard, Vanguard Marketing Corporation (VMC), the funds' advisors, and the funds have adopted Codes of Ethics designed to prevent employees who may have access to nonpublic information about the trading activities of the funds (access persons) from profiting from that information. The Codes permit access persons to invest in securities for their own accounts, including securities that may be held by a fund, but place substantive and procedural restrictions on the trading activities of access persons. For example, the Codes require that access persons receive advance approval for most securities trades to ensure that there is no conflict with the trading activities of the funds. The Codes also limit the ability of Vanguard employees to engage in short-term trading of Vanguard funds. Vanguard was established and operates under an Amended and Restated Funds' Service Agreement. The Amended and Restated Funds' Service Agreement provides as follows: (1) each Vanguard fund may be called upon to invest up to 0.40% of its current net assets in Vanguard, and (2) there is no other limitation on the dollar amount that each Vanguard fund may contribute to Vanguard's capitalization. The amounts that each fund has invested are adjusted from time to time in order to maintain the proportionate relationship between each fund's relative net assets and its contribution to Vanguard's capital. The Total Bond Market II Index Fund did not commence operations until January xx, 2009, and therefore has not contributed any capital to Vanguard as of the date of this SAI. MANAGEMENT. Corporate management and administrative services include: (1) executive staff; (2) accounting and financial; (3) legal and regulatory; (4) shareholder account maintenance; (5) monitoring and control of custodian B-23 relationships; (6) shareholder reporting; and (7) review and evaluation of advisory and other services provided to the funds by third parties. DISTRIBUTION. Vanguard Marketing Corporation, 400 Devon Park Drive A39, Wayne, PA 19087, a wholly-owned subsidiary of Vanguard, is the principal underwriter for the funds and in that capacity performs and finances marketing, promotional, and distribution activities (collectively, marketing and distribution activities) that are primarily intended to result in the sale of the funds' shares. VMC performs marketing and distribution activities at cost in accordance with the terms and conditions of a 1981 SEC exemptive order that permits the Vanguard funds to internalize and jointly finance the marketing, promotion, and distribution of their shares. Under the terms of the SEC order, the funds' trustees review and approve the marketing and distribution expenses incurred on their behalf, including the nature and cost of the activities and the desirability of each fund's continued participation in the joint arrangement. To ensure that each fund's participation in the joint arrangement falls within a reasonable range of fairness, each fund contributes to VMC's marketing and distribution expenses in accordance with an SEC-approved formula. Under that formula, one half of the marketing and distribution expenses are allocated among the funds based upon their relative net assets. The remaining half of those expenses is allocated among the funds based upon each fund's sales for the preceding 24 months relative to the total sales of the funds as a group; provided, however, that no fund's aggregate quarterly rate of contribution for marketing and distribution expenses shall exceed 125% of the average marketing and distribution expense rate for Vanguard, and that no fund shall incur annual marketing and distribution expenses in excess of 0.20 of 1% of its average month-end net assets. As of November 30, 2008, none of the Vanguard funds' allocated share of VMC's marketing and distribution expenses was greater than 0.03% of the fund's average month-end net assets. Each fund's contribution to these marketing and distribution expenses helps to maintain and enhance the attractiveness and viability of the Vanguard complex as a whole, which benefits all of the funds and their shareholders. VMC's principal marketing and distribution expenses are for advertising, promotional materials, and marketing personnel. Other marketing and distribution activities that VMC undertakes on behalf of the funds may include, but are not limited to: - Conducting or publishing Vanguard-generated research and analysis concerning the funds, other investments, the financial markets, or the economy; - Providing views, opinions, advice, or commentary concerning the funds, other investments, the financial markets, or the economy; - Providing analytical, statistical, performance, or other information concerning the funds, other investments, the financial markets, or the economy; - Providing administrative services in connection with investments in the funds or other investments, including, but not limited to, shareholder services, recordkeeping services, and educational services; - Providing products or services that assist investors or financial service providers (as defined below) in the investment decision-making process; - Providing promotional discounts, commission-free trading, fee waivers, and other benefits to clients of Vanguard Brokerage Services/(R)/ who maintain qualifying investments in the funds; and - Sponsoring, jointly sponsoring, financially supporting, or participating in conferences, programs, seminars, presentations, meetings, or other events involving fund shareholders, financial service providers, or others concerning the funds, other investments, the financial markets, or the economy, such as industry conferences, prospecting trips, due diligence visits, training or education meetings, and sales presentations. VMC performs most marketing and distribution activities itself. Some activities may be conducted by third parties pursuant to shared marketing arrangements under which VMC agrees to share the costs and performance of marketing and distribution activities in concert with a financial service provider. Financial service providers include, but are not limited to, investment advisors, broker-dealers, financial planners, financial consultants, banks, and insurance companies. Under these cost- and performance-sharing arrangements, VMC may pay or reimburse a financial service provider (or a third party it retains) for marketing and distribution activities that VMC would otherwise perform. VMC's cost- and performance-sharing arrangements may be established in connection with Vanguard investment products or services offered or provided to or through the financial service providers. VMC's arrangements for shared marketing and distribution activities may vary among financial service providers, and its payments or reimbursements to financial service providers in connection with shared marketing and distribution activities may be significant. VMC does not participate in the offshore arrangement Vanguard has established for qualifying Vanguard funds to be distributed in B-24 certain foreign countries on a private-placement basis to government-sponsored and other institutional investors through a third-party "asesor de inversiones" (investment advisor), which includes incentive-based remuneration. In connection with its marketing and distribution activities, VMC may give financial service providers (or their representatives): (1) promotional items of nominal value that display Vanguard's logo, such as golf balls, shirts, towels, pens, and mouse pads; (2) gifts that do not exceed $100 per person annually and are not preconditioned on achievement of a sales target; (3) an occasional meal, a ticket to a sporting event or the theater, or comparable entertainment that is neither so frequent nor so extensive as to raise any question of propriety and is not preconditioned on achievement of a sales target; and (4) reasonable travel and lodging accommodations to facilitate participation in marketing and distribution activities. VMC, as a matter of policy, does not pay asset-based fees, sales-based fees, or account-based fees to financial service providers in connection with its marketing and distribution activities for the Vanguard funds. VMC policy also prohibits marketing and distribution activities that are intended, designed, or likely to compromise suitability determinations by, or the fulfillment of any fiduciary duties or other obligations that apply to, financial service providers. Nonetheless, VMC's marketing and distribution activities are primarily intended to result in the sale of the funds' shares, and, as such, its activities, including shared marketing and distribution activities, may influence participating financial service providers (or their representatives) to recommend, promote, include, or invest in a Vanguard fund or share class. In addition, Vanguard or any of its subsidiaries may retain a financial service provider to provide consulting or other services, and that financial service provider also may provide services to investors. Investors should consider the possibility that any of these activities or relationships may influence a financial service provider's (or its representatives') decision to recommend, promote, include, or invest in a Vanguard fund or share class. Each financial service provider should consider its suitability determinations, fiduciary duties, and other legal obligations (or those of its representatives) in connection with any decision to consider, recommend, promote, include, or invest in a Vanguard fund or share class. Vanguard Total Bond Market II Index Fund did not commence operation until January xx, 2009, so expense information was not available as of the date of this SAI. OFFICERS AND TRUSTEES The Fund is governed by the board of trustees to the Trust and a single set of officers. The officers manage the day-to-day operations of the Fund under the direction of the Fund's board of trustees. The trustees set broad policies for the Fund; select investment advisors; monitor fund operations, performance, and costs; nominate and select new trustees; and elect fund officers. Each trustee serves the Fund until its termination; until the trustee's retirement, resignation, or death; or as otherwise specified in the Trust's organizational documents. Any trustee may be removed at a meeting of shareholders by a vote representing two-thirds of the total net asset value of all shares of the Trust. Each trustee also serves as a director of Vanguard. The following chart shows information for each trustee and executive officer of the Fund. The mailing address of the trustees and officers is P.O. Box 876, Valley Forge, PA 19482.

VANGUARD PRINCIPAL OCCUPATION(S) DURING THE POSITION(S) FUNDS' TRUSTEE/ PAST FIVE YEARS AND OUTSIDE DIRECTORSHIPS NUMBER OF VANGUARD FUNDS NAME, YEAR OF BIRTH HELD WITH FUNDS OFFICER SINCE OVERSEEN BY TRUSTEE/OFFICER ------------------- --------------- -------------- -------------------------- --------------------------- INTERESTED TRUSTEE INTERESTED TRUSTEE John J. Brennan/1/ Chairman of the May 1987 Chairman of the Board and Director 155 (1954) Board and Trustee (Trustee)of Vanguard and of each of the investment companies served by Vanguard; Chief Executive Officer and President of Vanguard (1996-2008). INDEPENDENT TRUSTEES Charles D. Ellis Trustee January 2001 Applecore Partners (pro bono ventures in education); 155 (1937) Senior Advisor to Greenwich Associates (international business strategy consulting); Successor Trustee of Yale University; Overseer of the Stern School of Business at New York University; Trustee of the Whitehead Institute for Biomedical Research. B-25 VANGUARD PRINCIPAL OCCUPATION(S) DURING THE POSITION(S) FUNDS' TRUSTEE/ PAST FIVE YEARS AND OUTSIDE DIRECTORSHIPS NUMBER OF VANGUARD FUNDS NAME, YEAR OF BIRTH HELD WITH FUNDS OFFICER SINCE OVERSEEN BY TRUSTEE/OFFICER ------------------- --------------- -------------- -------------------------- --------------------------- INDEPENDENT TRUSTEES Emerson U. Fullwood Trustee January 2008 Retired Executive Chief Staff and Marketing Officer for 155 (1948) North America and Corporate Vice President of Xerox Corporation (photocopiers and printers); Director of SPX Corporation (multi-industry manufacturing), of the United Way of Rochester, and of the Boy Scouts of America. Rajiv L. Gupta Trustee December 2001 Chairman, President, and Chief Executive Officer of Rohm 155 (1945) and Haas Co. (chemicals); Board Member of American Chemistry Council; Director of Tyco International, Ltd. (diversified manufacturing and services) since 2005. Amy Gutmann Trustee June 2006 President of the University of Pennsylvania; 155 (1949) Professor in the School of Arts and Sciences, Annenberg School for Communication, and Graduate School of Education of the University of Pennsylvania; Director of Carnegie Corporation of New York since 2005, and of Schuylkill River Development Corporation and Greater Philadelphia Chamber of Commerce; Trustee of the National Constitution Center since 2007. JoAnn Heffernan Heisen Trustee July 1998 Retired Corporate Vice President, Chief Global 155 (1950) Diversity Officer, and Member of the Executive Committee of Johnson & Johnson (pharmaceuticals/ consumer products); Vice President and Chief Information Officer (1977-2005) of Johnson & Johnson; Director of the University Medical Center at Princeton and Women's Research and Education Institute. Andre F. Perold Trustee December 2004 George Gund Professor of Finance and Banking, 155 (1952) Harvard Business School; Senior Associate Dean, Director of Faculty Recruiting, Harvard Business School; Director and Chairman of UNX, Inc. (equities trading firm); Chair of the Investment Committee of HighVista Strategies LLC (private investment firm) since 2005. Alfred M. Rankin, Jr. Trustee January 1993 Chairman, President, Chief Executive Officer, and 155 (1941) Director of NACCO Industries, Inc. (forklift trucks/ housewares/lignite); Director of Goodrich Corporation (industrial products/aircraft systems and services). J. Lawrence Wilson Trustee April 1985 Retired Chairman and Chief Executive Officer of 155 (1936) Rohm and Haas Co. (chemicals); Director of Cummins Inc.(diesel engines) and AmerisourceBergen Corp. (pharmaceutical distribution); Trustee of Vanderbilt University and of Culver Educational Foundation. B-26 VANGUARD PRINCIPAL OCCUPATION(S) DURING THE POSITION(S) FUNDS' TRUSTEE/ PAST FIVE YEARS AND OUTSIDE DIRECTORSHIPS NUMBER OF VANGUARD FUNDS NAME, YEAR OF BIRTH HELD WITH FUNDS OFFICER SINCE OVERSEEN BY TRUSTEE/OFFICER ------------------- --------------- -------------- -------------------------- --------------------------- EXECUTIVE OFFICERS Thomas J. Higgins/1/ Chief Financial July 1998 Principal of Vanguard; Chief Financial Officer 155 (1957) Officer of each of the investment companies served by Vanguard, since September 2008; Treasurer of each of the investmentcompanies served by Vanguard (1998--2008). Kathryn J. Hyatt/1/ Treasurer November 2008 Principal of Vanguard; Treasurer of each of the (1955) investment companies served by Vanguard, since November 2008; Assistant Treasurer of each of the investment companies served by Vanguard (1988-2008). F. William McNabb III/1/ Chief Executive March 2008 Chief Executive Officer of Vanguard since August 31, 2008; 155 (1957) Officer and Director and President of Vanguard since March 2008; President Chief Executive Officer and President of each of the investment companies served by Vanguard, since March 2008; Director of VMC; Managing Director of Vanguard (1995-2008). Heidi Stam/1/ Secretary July 2005 Managing Director of Vanguard since 2006; General Counsel 155 (1956) of Vanguard since 2005; Secretary of Vanguard and of each of the investment companies served by Vanguard, since 2005; Director and Senior Vice President of VMC since 2005; Principal of Vanguard (1997-2006). 1 Officers of the Funds are "interested persons" as defined in the 1940 Act.

Mr. Ellis is a Senior Advisor to Greenwich Associates, a firm that consults on business strategy to professional financial services organizations in markets around the world. A large number of financial service providers, including Vanguard, subscribe to programs of research-based consulting. During calendar years 2006 and 2007, Vanguard paid Greenwich subscription fees amounting to less than $610,000. Vanguard's subscription rates are similar to those of other subscribers. Board Committees: The Trust's board has the following committees: - Audit Committee: This committee oversees the accounting and financial reporting policies, the systems of internal controls, and the independent audits of each fund and Vanguard. All independent trustees serve as members of the committee. - Compensation Committee: This committee oversees the compensation programs established by each fund and Vanguard for the benefit of their employees, officers, and trustees/directors. All independent trustees serve as members of the committee. - Nominating Committee: This committee nominates candidates for election to Vanguard's board of directors and the board of trustees of each fund (collectively, the Vanguard boards). The committee also has the authority to recommend the removal of any director or trustee from the Vanguard boards. All independent trustees serve as members of the committee. The Nominating Committee will consider shareholder recommendations for trustee nominees. Shareholders may send recommendations to Mr. Rankin, Chairman of the Committee. TRUSTEE COMPENSATION The same individuals serve as trustees of all Vanguard funds and each fund pays a proportionate share of the trustees' compensation. The funds also employ their officers on a shared basis; however, officers are compensated by Vanguard, not the funds. B-27 INDEPENDENT TRUSTEES. The funds compensate their independent trustees (i.e., the ones who are not also officers of the funds) in three ways: - The independent trustees receive an annual fee for their service to the funds, which is subject to reduction based on absences from scheduled board meetings. - The independent trustees are reimbursed for the travel and other expenses that they incur in attending board meetings. - Upon retirement (after attaining age 65 and completing five years of service), the independent trustees who began their service prior to January 1, 2001, receive a retirement benefit under a separate account arrangement. As of January 1, 2001, the opening balance of each eligible trustee's separate account was generally equal to the net present value of the benefits he or she had accrued under the trustees' former retirement plan. Each eligible trustee's separate account will be credited annually with interest at a rate of 7.5% until the trustee receives his or her final distribution. Those independent trustees who began their service on or after January 1, 2001, are not eligible to participate in the plan. "INTERESTED" TRUSTEE. Mr. Brennan serves as a trustee, but is not paid in this capacity. He is, however, paid in his role as an officer of Vanguard. COMPENSATION TABLE. The following table provides compensation details for each of the trustees.The trustees did not receive compensation or retirement benefits from the Fund as of the date of this Statement of Additional Information, because the Fund did not commence operations until January xx, 2009. We list the amounts paid as compensation and accrued as retirement benefits by the Funds for each trustee. In addition, the table shows the total amount of benefits that we expect each trustee to receive from all Vanguard funds upon retirement, and the total amount of compensation paid to each trustee by all Vanguard funds. VANGUARD BOND INDEX FUNDS TRUSTEES' COMPENSATION TABLE

Pension or Retirement Aggregate Benefits Accrued as Accrued Annual Total Compensation Compensation from Part of these Retirement Benefit at from All Vanguard Funds Trustee the Funds Funds' Expenses January 1, 2007/(1)/ Paid to Trustees/(2)/ ---------- ------------------ --------------------- ---------------------- --------------------- John J. Brennan -- -- -- -- Charles D. Ellis -- -- -- $145,000 Emerson U. Fullwood/3/ -- -- -- -- Rajiv L. Gupta -- -- -- 145,000 Amy Gutmann -- -- -- 145,000 JoAnn Heffernan Heisen -- -- $2,542 145,000 Andre F. Perold -- -- -- 145,000 Alfred M. Rankin, Jr. -- -- 4,982 168,000 J. Lawrence Wilson -- -- 7,240 140,900 1 Each trustee is eligible to receive retirement benefits only after completing at least 5 years (60 consecutive months) of service as a trustee for the Vanguard funds. The annual retirement benefit will be paid in monthly installments, beginning with the month following the trustee's retirement from service, and will cease after 10 years of payments (120 monthly installments). Trustees who began their service on or after January 1, 2001, are not eligible to participate in the retirement benefit plan. 2 The amounts reported in this column reflect the total compensation paid to each trustee for his or her service as trustee of 152 Vanguard funds for the 2007 calendar year. 3 Mr. Fullwood became a member of the Fund's board effective January 2008.

B-28 OWNERSHIP OF FUND SHARES All trustees allocate their investments among the various Vanguard funds based on their own investment needs. The following table shows each trustee's ownership of all Vanguard funds served by the trustee as of December 31, 2007. Vanguard Total Bond Market II Index Fund did not commence operations until January xx, 2009, and therefore no information is presented for that Fund.

DOLLAR RANGE AGGREGATE DOLLAR RANGE OF OF FUND SHARES VANGUARD FUND SHARES FUND TRUSTEE OWNED BY TRUSTEE OWNED BY TRUSTEE VANGUARD Total Bond Market II Index Fund John J. Brennan -- Over $100,000 Charles D. Ellis -- Over $100,000 Emerson U. Fullwood /1/ -- Over $100,000 Rajiv L. Gupta -- Over $100,000 Amy Gutmann -- Over $100,000 JoAnn Heffernan Heisen -- Over $100,000 Andre F. Perold -- Over $100,000 Alfred M. Rankin, Jr. -- Over $100,000 J. Lawrence Wilson -- Over $100,000

PORTFOLIO HOLDINGS DISCLOSURE POLICIES AND PROCEDURES INTRODUCTION Vanguard and the Boards of Trustees of the Vanguard funds (Boards) have adopted Portfolio Holdings Disclosure Policies and Procedures (Policies and Procedures) to govern the disclosure of the portfolio holdings of each Vanguard fund. Vanguard and the Boards considered each of the circumstances under which Vanguard fund portfolio holdings may be disclosed to different categories of persons under the Policies and Procedures. Vanguard and the Boards also considered actual and potential material conflicts that could arise in such circumstances between the interests of Vanguard fund shareholders, on the one hand, and those of the fund's investment advisor, distributor, or any affiliated person of the fund, its investment advisor, or its distributor, on the other. After giving due consideration to such matters and after the exercise of their fiduciary duties and reasonable business judgment, Vanguard and the Boards determined that the Vanguard funds have a legitimate business purpose for disclosing portfolio holdings to the persons described in each of the circumstances set forth in the Policies and Procedures and that the Policies and Procedures are reasonably designed to ensure that disclosure of portfolio holdings and information about portfolio holdings is in the best interests of fund shareholders and appropriately addresses the potential for material conflicts of interest. The Boards exercise continuing oversight of the disclosure of Vanguard fund portfolio holdings by (1) overseeing the implementation and enforcement of the Policies and Procedures, the Code of Ethics, and the Policies and Procedures Designed to Prevent the Misuse of Inside Information (collectively, the portfolio holdings governing policies) by the Chief Compliance Officer of Vanguard and the Vanguard funds; (2) considering reports and recommendations by the Chief Compliance Officer concerning any material compliance matters (as defined in Rule 38a-1 under the 1940 Act and Rule 206(4)-7 under the Investment Advisers Act of 1940) that may arise in connection with any portfolio holdings governing policies; and (3) considering whether to approve or ratify any amendment to any portfolio holdings governing policies. Vanguard and the Boards reserve the right to amend the Policies and Procedures at any time and from time to time without prior notice at their sole discretion. For purposes of the Policies and Procedures, the term "portfolio holdings" means the equity and debt securities (e.g., stocks and bonds) held by a Vanguard fund and does not mean the cash investments, derivatives, and other investment positions (collectively, other investment positions) held by the fund. ONLINE DISCLOSURE OF TEN LARGEST STOCK HOLDINGS Each of the Vanguard equity funds and Vanguard balanced funds generally will seek to disclose the fund's ten largest stock portfolio holdings and the percentages that each of these ten largest stock portfolio holdings represents of the fund's total B-29 assets as of the most recent calendar-quarter-end (quarter-end ten largest stock holdings) online at www.vanguard.com in the "Portfolio" section of the fund's Portfolio & Management page, 15 calendar days after the end of the calendar quarter. In addition, those funds generally will seek to disclose the fund's ten largest stock portfolio holdings as of the most recent month-end (month-end ten largest stock holdings, and together with quarter-end ten largest stock holdings, ten largest stock holdings) online at www.vanguard.com in the "Portfolio" section of the fund's Portfolio & Management page, 10 business days after the end of the month. Online disclosure of the ten largest stock holdings is made to all categories of persons, including individual investors, institutional investors, intermediaries, third-party service providers, rating and ranking organizations, affiliated persons of a Vanguard fund, and all other persons. ONLINE DISCLOSURE OF COMPLETE PORTFOLIO HOLDINGS Each of the Vanguard funds, excluding Vanguard money market funds and Vanguard Market Neutral Fund, generally will seek to disclose the fund's complete portfolio holdings (complete portfolio holdings) as of the most recent calendar-quarter-end online at www.vanguard.com in the "Portfolio" section of the fund's Portfolio & Management page, 30 calendar days after the end of the calendar quarter. Vanguard Market Neutral Fund generally will seek to disclose the Fund's complete portfolio holdings as of the most recent calendar-quarter-end online at www.vanguard.com, in the "Holdings" section of the Fund's Profile page, 60 calendar days after the end of the calendar quarter. Online disclosure of complete portfolio holdings is made to all categories of persons, including individual investors, institutional investors, intermediaries, third-party service providers, rating and ranking organizations, affiliated persons of a Vanguard fund, and all other persons. Vanguard's Portfolio Review Department will review complete portfolio holdings before online disclosure is made as described above and, after consultation with a Vanguard fund's investment advisor, may withhold any portion of the fund's complete portfolio holdings from online disclosure as described above when deemed to be in the best interests of the fund. DISCLOSURE OF COMPLETE PORTFOLIO HOLDINGS TO SERVICE PROVIDERS SUBJECT TO CONFIDENTIALITY AND TRADING RESTRICTIONS Vanguard, for legitimate business purposes, may disclose Vanguard fund complete portfolio holdings at times it deems necessary and appropriate to rating and ranking organizations, financial printers, proxy voting service providers, pricing information vendors, third parties that deliver analytical, statistical, or consulting services, and other third parties that provide services (collectively, Service Providers) to Vanguard, Vanguard subsidiaries, and/or the Vanguard funds. Disclosure of complete portfolio holdings to a Service Provider is conditioned on the Service Provider being subject to a written agreement imposing a duty of confidentiality, including a duty not to trade on the basis of any material nonpublic information. The frequency with which complete portfolio holdings may be disclosed to a Service Provider, and the length of the lag, if any, between the date of the information and the date on which the information is disclosed to the Service Provider, is determined based on the facts and circumstances, including, without limitation, the nature of the portfolio holdings information to be disclosed, the risk of harm to the funds and their shareholders, and the legitimate business purposes served by such disclosure. The frequency of disclosure to a Service Provider varies and may be as frequent as daily, with no lag. Disclosure of Vanguard fund complete portfolio holdings by Vanguard to a Service Provider must be authorized by a Vanguard fund officer or a Principal in Vanguard's Portfolio Review or Legal Department. Any disclosure of Vanguard fund complete portfolio holdings to a Service Provider as described previously may also include a list of the other investment positions that make up the fund, such as cash investments and derivatives. As of March 31, 2007, Vanguard fund complete portfolio holdings are disclosed to the following Service Providers as part of ongoing arrangements that serve legitimate business purposes: Abel/Noser Corporation, Advisor Software, Inc., Alcom Printing Group Inc., Apple Press, L.C., Broadridge Financial Solutions, Inc., Brown Brothers Harriman & Co., FactSet Research Systems Inc., Intelligencer Printing Company, Investment Technology Group, Inc., Lipper, Inc., McMunn Associates Inc., Pitney Bowes Management Services, Reuters America Inc., R.R. Donnelley, Inc., State Street Bank and Trust Company, Triune Color Corporation, and Tursack Printing Inc. DISCLOSURE OF COMPLETE PORTFOLIO HOLDINGS TO VANGUARD AFFILIATES AND CERTAIN FIDUCIARIES SUBJECT TO CONFIDENTIALITY AND TRADING RESTRICTIONS Vanguard fund complete portfolio holdings may be disclosed between and among the following persons (collectively, Affiliates and Fiduciaries) for legitimate business purposes within the scope of their official duties and responsibilities, B-30 subject to such persons' continuing legal duty of confidentiality and legal duty not to trade on the basis of any material nonpublic information, as such duties are imposed under the Code of Ethics, the Policies and Procedures Designed to Prevent the Misuse of Inside Information, by agreement, or under applicable laws, rules, and regulations: (1) persons who are subject to the Code of Ethics or the Policies and Procedures Designed to Prevent the Misuse of Inside Information; (2) an investment advisor, distributor, administrator, transfer agent, or custodian to a Vanguard fund; (3) an accounting firm, an auditing firm or outside legal counsel retained by Vanguard, a Vanguard subsidiary, or a Vanguard fund; (4) an investment advisor to whom complete portfolio holdings are disclosed for due diligence purposes when the advisor is in merger or acquisition talks with a Vanguard fund's current advisor; and (5) a newly hired investment advisor or sub-advisor to whom complete portfolio holdings are disclosed prior to the time it commences its duties. The frequency with which complete portfolio holdings may be disclosed between and among Affiliates and Fiduciaries, and the length of the lag, if any, between the date of the information and the date on which the information is disclosed between and among the Affiliates and Fiduciaries, is determined by such Affiliates and Fiduciaries based on the facts and circumstances, including, without limitation, the nature of the portfolio holdings information to be disclosed, the risk of harm to the funds and their shareholders, and the legitimate business purposes served by such disclosure. The frequency of disclosure between and among Affiliates and Fiduciaries varies and may be as frequent as daily, with no lag. Any disclosure of Vanguard fund complete portfolio holdings to any Affiliates and Fiduciaries as previously described above may also include a list of the other investment positions that make up the fund, such as cash investments and derivatives. Disclosure of Vanguard fund complete portfolio holdings or other investment positions by Vanguard, Vanguard Marketing Corporation, or a Vanguard fund to Affiliates and Fiduciaries must be authorized by a Vanguard fund officer or a Principal of Vanguard. As of March 31, 2007, Vanguard fund complete portfolio holdings are disclosed to the following Affiliates and Fiduciaries as part of ongoing arrangements that serve legitimate business purposes: Vanguard, and each investment advisor, custodian, and independent registered public accounting firm identified in this Statement of Additional Information. DISCLOSURE OF PORTFOLIO HOLDINGS TO BROKER-DEALERS IN THE NORMAL COURSE OF MANAGING A FUND'S ASSETS An investment advisor, administrator, or custodian for a Vanguard fund may, for legitimate business purposes within the scope of its official duties and responsibilities, disclose portfolio holdings (whether partial portfolio holdings or complete portfolio holdings) and other investment positions that make up the fund to one or more broker-dealers during the course of, or in connection with, normal day-to-day securities and derivatives transactions with or through such broker-dealers subject to the broker-dealer's legal obligation not to use or disclose material nonpublic information concerning the fund's portfolio holdings, other investment positions, securities transactions, or derivatives transactions without the consent of the fund or its agents. The Vanguard funds have not given their consent to any such use or disclosure and no person or agent of Vanguard is authorized to give such consent except as approved in writing by the Boards of the Vanguard funds. Disclosure of portfolio holdings or other investment positions by Vanguard to broker-dealers must be authorized by a Vanguard fund officer or a Principal of Vanguard. DISCLOSURE OF NON-MATERIAL INFORMATION The Policies and Procedures permit Vanguard fund officers, Vanguard fund portfolio managers, and other Vanguard representatives (collectively, Approved Vanguard Representatives) to disclose any views, opinions, judgments, advice or commentary, or any analytical, statistical, performance, or other information, in connection with or relating to a Vanguard fund or its portfolio holdings and/or other investment positions (collectively, commentary and analysis) or any changes in the portfolio holdings of a Vanguard fund that occurred after the most recent calendar-quarter end (recent portfolio changes) to any person if (1) such disclosure serves a legitimate business purpose, (2) such disclosure does not effectively result in the disclosure of the complete portfolio holdings of any Vanguard fund (which can be disclosed only in accordance with the Policies and Procedures), and (3) such information does not constitute material nonpublic information. Disclosure of commentary and analysis or recent portfolio changes by Vanguard, Vanguard Marketing Corporation, or a Vanguard fund must be authorized by a Vanguard fund officer or a Principal of Vanguard. An Approved Vanguard Representative must make a good faith determination whether the information constitutes material nonpublic information, which involves an assessment of the particular facts and circumstances. Vanguard believes that in most cases recent portfolio changes that involve a few or even several securities in a diversified portfolio or commentary and analysis would be immaterial and would not convey any advantage to a recipient in making an B-31 investment decision concerning a Vanguard fund. Nonexclusive examples of commentary and analysis about a Vanguard fund include (1) the allocation of the fund's portfolio holdings and other investment positions among various asset classes, sectors, industries, and countries; (2) the characteristics of the stock and bond components of the fund's portfolio holdings and other investment positions; (3) the attribution of fund returns by asset class, sector, industry, and country; and (4) the volatility characteristics of the fund. Approved Vanguard Representatives may at their sole discretion determine whether to deny any request for information made by any person, and may do so for any reason or for no reason. "Approved Vanguard Representatives" include, for purposes of the Policies and Procedures, persons employed by or associated with Vanguard or a subsidiary of Vanguard who have been authorized by Vanguard's Portfolio Review Department to disclose recent portfolio changes and/or commentary and analysis in accordance with the Policies and Procedures. As of March 31, 2007, Vanguard non-material portfolio holdings information is disclosed to KPMG, LLP, and R.V. Kuhns & Associates. DISCLOSURE OF PORTFOLIO HOLDINGS IN ACCORDANCE WITH SEC EXEMPTIVE ORDERS Vanguard's Fund Financial Services unit may disclose to the National Securities Clearing Corporation (NSCC) the daily portfolio composition files (PCFs) that identify a basket of specified securities which may overlap with the actual or expected portfolio holdings of the Vanguard funds (ETF Funds) that offer a class of shares known as Vanguard ETF Shares in accordance with the terms and conditions of related exemptive orders (Vanguard ETF Exemptive Orders) issued by the Securities and Exchange Commission (SEC), as described further below. Unlike the conventional classes of shares issued by ETF Funds, the ETF Shares are listed for trading on a national securities exchange. Each ETF Fund issues ETF Shares in large blocks, known as "Creation Units." To purchase or redeem a Creation Unit, an investor must be an "Authorized Participant" or it must do so through a broker-dealer that is an Authorized Participant. An Authorized Participant is a participant in the Depository Trust Company (DTC) that has executed a Participant Agreement with Vanguard Marketing Corporation. Each ETF Fund issues Creation Units in exchange for a "portfolio deposit" consisting of a basket of specified securities (Deposit Securities) and a cash payment (the Balancing Amount). Each ETF Fund also redeems Creation Units in kind; an investor who tenders a Creation Unit will receive, as redemption proceeds, a basket of specified securities together with a Balancing Amount. In connection with the creation and redemption process, and in accordance with the terms and conditions of the Vanguard ETF Exemptive Orders, Vanguard makes available to the NSCC, for dissemination to NSCC participants on each business day prior to the opening of trading on the exchange, a PCF containing a list of the names and the required number of shares of each Deposit Security for each ETF Fund. (The NSCC is a clearing agency registered with the SEC and affiliated with DTC.) In addition, the exchange disseminates (1) continuously throughout the trading day, through the facilities of the consolidated tape, the market value of an ETF Share, and (2) every 15 seconds throughout the trading day, separately from the consolidated tape, a calculation of the estimated NAV of an ETF Share (which estimate is expected to be accurate to within a few basis points). Comparing these two figures allows an investor to determine whether, and to what extent, ETF Shares are selling at a premium or at a discount to NAV. ETF Shares are listed on the exchange and traded in the secondary market in the same manner as other equity securities. The price of ETF Shares trading on the secondary market is based on a current bid/offer market. As contemplated by the Vanguard ETF Exemptive Orders, Vanguard and the ETF Funds expect that only institutional arbitrageurs and institutional investors with large indexed portfolios will buy and sell ETF Shares in Creation Unit-sized aggregations because Creation Units can be purchased only in exchange for securities likely to cost millions of dollars. An exchange specialist, in providing for a fair and orderly secondary market for ETF Shares, also may purchase Creation Units for use in its market-making activities on the exchange. Vanguard and the ETF Funds expect secondary market purchasers of ETF Shares will include both institutional and retail investors. Vanguard and the ETF Funds believe that arbitrageurs will purchase or redeem Creation Units to take advantage of discrepancies between the ETF Shares' market price and the ETF Shares' underlying NAV. Vanguard and the ETF Funds expect that this arbitrage activity will provide a market "discipline" that will result in a close correspondence between the price at which the ETF Shares trade and their NAV. In other words, Vanguard and the ETF Funds do not expect the ETF Shares to trade at a significant premium or discount to their NAV. In addition to making PCFs available to the NSCC, as previously described, Vanguard's Fund Financial Services unit may disclose the PCF for any ETF Fund to any person, or online at www.vanguard.com to all categories of persons, if B-32 (1) such disclosure serves a legitimate business purpose and (2) such disclosure does not constitute material nonpublic information. Vanguard's Fund Financial Services unit must make a good faith determination whether the PCF for any ETF Fund constitutes material nonpublic information, which involves an assessment of the particular facts and circumstances. Vanguard believes that in most cases the PCF for any ETF Fund would be immaterial and would not convey any advantage to the recipient in making an investment decision concerning the ETF Fund if sufficient time has passed between the date of the PCF and the date on which the PCF is disclosed. Vanguard's Fund Financial Services unit may at its sole discretion determine whether to deny any request for the PCF for any ETF Fund made by any person, and may do so for any reason or for no reason. Disclosure of a PCF must be authorized by a Vanguard fund officer or a Principal in Vanguard's Fund Financial Services unit. DISCLOSURE OF PORTFOLIO HOLDINGS RELATED INFORMATION TO THE ISSUER OF A SECURITY FOR LEGITIMATE BUSINESS PURPOSES Vanguard, at its sole discretion, may disclose portfolio holdings information concerning a security held by one or more Vanguard funds to the issuer of such security if the issuer presents, to the satisfaction of Fund Financial Services, convincing evidence that the issuer has a legitimate business purpose for such information. Disclosure of this information to an issuer is conditioned on the issuer being subject to a written agreement imposing a duty of confidentiality, including a duty not to trade on the basis of any material nonpublic information. The frequency with which portfolio holdings information concerning a security may be disclosed to the issuer of such security, and the length of the lag, if any, between the date of the information and the date on which the information is disclosed to the issuer, is determined based on the facts and circumstances, including, without limitation, the nature of the portfolio holdings information to be disclosed, the risk of harm to the funds and their shareholders, and the legitimate business purposes served by such disclosure. The frequency of disclosure to an issuer cannot be determined in advance of a specific request and will vary based upon the particular facts and circumstances and the legitimate business purposes, but in unusual situations could be as frequent as daily, with no lag. Disclosure of portfolio holdings information concerning a security held by one or more Vanguard funds to the issuer of such security must be authorized by a Vanguard fund officer or a Principal in Vanguard's Portfolio Review or Legal Department. DISCLOSURE OF PORTFOLIO HOLDINGS AS REQUIRED BY APPLICABLE LAW Vanguard fund portfolio holdings (whether partial portfolio holdings or complete portfolio holdings) and other investment positions that make up a fund shall be disclosed to any person as required by applicable laws, rules, and regulations. Examples of such required disclosure include, but are not limited to, disclosure of Vanguard fund portfolio holdings (1) in a filing or submission with the SEC or another regulatory body, (2) in connection with seeking recovery on defaulted bonds in a federal bankruptcy case, (3) in connection with a lawsuit, or (4) as required by court order. Disclosure of portfolio holdings or other investment positions by Vanguard, Vanguard Marketing Corporation, or a Vanguard fund as required by applicable laws, rules, and regulations must be authorized by a Vanguard fund officer or a Principal of Vanguard. PROHIBITIONS ON DISCLOSURE OF PORTFOLIO HOLDINGS No person is authorized to disclose Vanguard fund portfolio holdings or other investment positions (whether online at www.vanguard.com, in writing, by fax, by e-mail, orally, or by other means) except in accordance with the Policies and Procedures. In addition, no person is authorized to make disclosure pursuant to the Policies and Procedures if such disclosure is otherwise unlawful under the antifraud provisions of the federal securities laws (as defined in Rule 38a-1 under the 1940 Act). Furthermore, Vanguard's management, at its sole discretion, may determine not to disclose portfolio holdings or other investment positions that make up a Vanguard fund to any person who would otherwise be eligible to receive such information under the Policies and Procedures, or may determine to make such disclosures publicly as provided by the Policies and Procedures. PROHIBITIONS ON RECEIPT OF COMPENSATION OR OTHER CONSIDERATION The Policies and Procedures prohibit a Vanguard fund, its investment advisor, and any other person from paying or receiving any compensation or other consideration of any type for the purpose of obtaining disclosure of Vanguard fund portfolio holdings or other investment positions. "Consideration" includes any agreement to maintain assets in the fund B-33 or in other investment companies or accounts managed by the investment advisor or by any affiliated person of the investment advisor. INVESTMENT ADVISORY SERVICES The Fund receives all investment advisory services from Vanguard, through its Fixed Income Group. These services are provided on an at-cost basis from an experienced advisory staff employed directly by Vanguard. The compensation and other expenses of the advisory staff are allocated among the funds utilizing these services. Vanguard Total Bond Market II Index Fund did not commence operations until January xx, 2009, and therefore did not have any advisory expenses as of the date of this SAI. OTHER ACCOUNTS MANAGED Kenneth E. Volpert co-manages the Total Bond Market II Index Fund, which commenced operations on January xx, 2009. Mr. Volpert co-managed seven other registered investment companies with total assets of $97.9 billion and co-managed eleven other pooled investment vehicles with total assets of $7.5 billion, as of November 30, 2008 (advisory fees not based on performance). Gregory Davis co-manages the Total Bond Market II Index Fund, which commenced operations on January xx, 2009. Mr. Davis managed or co-managed five other registered investment companies with total assets of $82.1 billion and co-managed eleven other pooled investment vehicles with total assets of $7.5 billion, as of November 30, 2008 (advisory fees not based on performance). MATERIAL CONFLICTS OF INTEREST At Vanguard, individual portfolio managers may manage multiple accounts for multiple clients. In addition to mutual funds, these other accounts may include separate accounts, collective trusts, or offshore funds. Managing multiple accounts may give rise to potential conflicts of interest, including, for example, conflicts among investment strategies and conflicts in the allocation of investment opportunities. Vanguard manages potential conflicts between funds or with other types of accounts through allocation policies and procedures, internal review processes, and oversight by directors and independent third parties. Vanguard has developed trade allocation procedures and controls to ensure that no one client, regardless of type, is intentionally favored at the expense of another. Allocation policies are designed to address potential conflicts in situations where two or more funds or accounts participate in investment decisions involving the same securities. DESCRIPTION OF COMPENSATION The Fund's portfolio managers are Vanguard employees. This section describes the compensation of Vanguard employees who manage Vanguard mutual funds. As of November 30, 2008, a Vanguard portfolio manager's compensation generally consists of base salary, bonus, and payments under Vanguard's long-term incentive compensation program. In addition, portfolio managers are eligible for the standard retirement benefits and health and welfare benefits available to all Vanguard employees. Also, certain portfolio managers may be eligible for additional retirement benefits under several supplemental retirement plans that Vanguard adopted in the 1980's to restore dollar-for-dollar the benefits of management employees that had been cut back solely as a result of tax law changes. These plans are structured to provide the same retirement benefits as the standard retirement plans. In the case of portfolio managers responsible for managing multiple Vanguard funds or accounts, the method used to determine their compensation is the same for all funds and investment accounts. A portfolio manager's base salary is determined by the manager's experience and performance in the role, taking into account the ongoing compensation benchmark analyses performed by the Vanguard Human Resources Department. A portfolio manager's base salary is generally a fixed amount that may change as a result of an annual review, upon assumption of new duties, or when a market adjustment of the position occurs. A portfolio manager's bonus is determined by a number of factors. One factor is gross, pre-tax performance of the fund relative to expectations for how the fund should have performed, given the fund's investment objective, policies, strategies, and limitations, and the market environment during the measurement period. This performance factor is not based on the value of assets held in the fund's portfolio. For the Total Bond Market II Index Fund, the performance factor B-34 depends on how closely the portfolio manager tracks the fund's target index (Barclays Capital U.S. Aggregate Bond Index) over a one-year period. Additional factors include the portfolio manager's contributions to the investment management functions within the sub-asset class, contributions to the development of other investment professionals and supporting staff, and overall contributions to strategic planning and decisions for the investment group. The target bonus is expressed as a percentage of base salary. The actual bonus paid may be more or less than the target bonus, based on how well the manager satisfies the objectives stated above. The bonus is paid on an annual basis. Under the long-term incentive compensation program, all full-time employees receive a payment from Vanguard's long-term incentive compensation plan based on their years of service, job level and, if applicable, management responsibilities. Each year, Vanguard's independent directors determine the amount of the long term incentive compensation award for that year based on the investment performance of the Vanguard funds relative to competitors and Vanguard's operating efficiencies in providing services to the Vanguard funds. OWNERSHIP OF SECURITIES Vanguard employees, including portfolio managers, allocate their investments among the various Vanguard funds based on their own individual investment needs and goals. Vanguard employees as a group invest a sizeable portion of their personal assets in Vanguard funds. As of November 30, 2008, Vanguard employees collectively invested $1.6 billion in Vanguard funds. John J. Brennan, Chairman of the Board of Vanguard and the Vanguard funds, F. William McNabb III, Chief Executive Officer and President of Vanguard and the Vanguard funds; and George U. Sauter, Chief Investment Officer and Managing Director of Vanguard, invest substantially all of their personal financial assets in Vanguard funds. DURATION AND TERMINATION OF INVESTMENT ADVISORY AGREEMENT Vanguard provides at-cost investment advisory services to the Fund pursuant to the terms of the Fourth Amended and Restated Funds' Service Agreement. This agreement will continue in full force and effect until terminated or amended by mutual agreement of the Vanguard funds and Vanguard. PORTFOLIO TRANSACTIONS The advisor decides which securities to buy and sell on behalf of the Fund and then selects the brokers or dealers that will execute the trades on an agency basis or the dealers with whom the trades will be effected on a principal basis. For each trade, the advisor must select a broker-dealer that it believes will provide "best execution." Best execution does not necessarily mean paying the lowest spread or commission rate available. In seeking best execution, the SEC has said that an advisor should consider the full range of a broker-dealer's services. The factors considered by the advisor in seeking best execution include, but are not limited to, the broker-dealer's execution capability, clearance and settlement services, commission rate, trading expertise, willingness and ability to commit capital, ability to provide anonymity, financial responsibility, reputation and integrity, responsiveness, access to underwritten offerings and secondary markets, and access to company management, as well as the value of any research provided by the broker-dealer. In assessing which broker-dealer can provide best execution for a particular trade, the advisor also may consider the timing and size of the order and available liquidity and current market conditions. Subject to applicable legal requirements, the advisor may select a broker based partly on brokerage or research services provided to the advisor and its clients, including the Fund. The advisor may cause the Fund to pay a higher commission than other brokers would charge if the advisor determines in good faith that the amount of the commission is reasonable in relation to the value of services provided. The advisor also may receive brokerage or research services from broker-dealers that are provided at no charge in recognition of the volume of trades directed to the broker. To the extent research services or products may be a factor in selecting brokers, services and products may include written research reports analyzing performance or securities, discussions with research analysts, meetings with corporate executives to obtain oral reports on company performance, market data, and other products and services that will assist the advisor in its investment decision-making process. The research services provided by brokers through which the Fund effects securities transactions may be used by the advisor in servicing all of its accounts, and some of the services may not be used by the advisor in connection with the Fund. The types of securities in which the Fund invests are generally purchased and sold through principal transactions, meaning that the Fund normally purchase securities directly from the issuer or a primary market-maker acting as principal for the securities on a net basis. Explicit brokerage commissions are not paid on these transactions, although purchases of new issues from underwriters of securities typically include a commission or concession paid by the issuer B-35 to the underwriter, and purchases from dealers serving as market-makers typically include a dealer's mark-up (i.e., a spread between the bid and the asked prices). Some securities that are considered for investment by the Fund may also be appropriate for other Vanguard funds or for other clients served by the advisor. If such securities are compatible with the investment policies of the Fund and one or more of the advisor's other clients, and are considered for purchase or sale at or about the same time, then transactions in such securities will be aggregated by the advisor and the purchased securities or sale proceeds will be allocated among the participating Vanguard funds and the other participating clients of the advisor in a manner deemed equitable by the advisor. Although there may be no specified formula for allocating such transactions, the allocation methods used, and the results of such allocations, will be subject to periodic review by the Fund's board of trustees. Vanguard Total Bond Market II Index Fund did not commence operations until January xx, 2009, so brokerage information was not available as of the date of this SAI. PROXY VOTING GUIDELINES The Board of Trustees (the Board) of each Vanguard fund that invests in stocks has adopted proxy voting procedures and guidelines to govern proxy voting by the fund. The Board has delegated oversight of proxy voting to the Proxy Oversight Committee (the Committee), made up of senior officers of Vanguard, a majority of whom are also officers of each Vanguard fund, and subject to the operating procedures and guidelines described below. The Committee reports directly to the Board. Vanguard is subject to these guidelines to the extent the guidelines call for Vanguard to administer the voting process and implement the resulting voting decisions, and for these purposes have been approved by the Board of Directors of Vanguard. The overarching objective in voting is simple: to support proposals and director nominees that maximize the value of a fund's investments--and those of fund shareholders--over the long term. While the goal is simple, the proposals the funds receive are varied and frequently complex. As such, the guidelines adopted by the Board provide a rigorous framework for assessing each proposal. Under the guidelines, each proposal must be evaluated on its merits, based on the particular facts and circumstances as presented. For ease of reference, the procedures and guidelines often refer to all funds. However, our processes and practices seek to ensure that proxy voting decisions are suitable for individual funds. For most proxy proposals, particularly those involving corporate governance, the evaluation will result in the same position being taken across all of the funds and the funds voting as a block. In some cases, however, a fund may vote differently, depending upon the nature and objective of the fund, the composition of its portfolio, and other factors. The guidelines do not permit the Board to delegate voting responsibility to a third party that does not serve as a fiduciary for the funds. Because many factors bear on each decision, the guidelines incorporate factors the Committee should consider in each voting decision. A fund may refrain from voting if that would be in the fund's and its shareholders' best interests. These circumstances may arise, for example, if the expected cost of voting exceeds the expected benefits of voting, or if exercising the vote would result in the imposition of trading or other restrictions. In evaluating proxy proposals, we consider information from many sources, including but not limited to the investment advisor for the fund, management or shareholders of a company presenting a proposal, and independent proxy research services. We will give substantial weight to the recommendations of the company's board, absent guidelines or other specific facts that would support a vote against management. In all cases, however, the ultimate decision rests with the members of the Proxy Oversight Committee, who are accountable to the fund's Board. While serving as a framework, the following guidelines cannot contemplate all possible proposals with which a fund may be presented. In the absence of a specific guideline for a particular proposal (e.g., in the case of a transactional issue or contested proxy), the Committee will evaluate the issue and cast the fund's vote in a manner that, in the Committee's view, will maximize the value of the fund's investment, subject to the individual circumstances of the fund. I. THE BOARD OF DIRECTORS A. ELECTION OF DIRECTORS Good governance starts with a majority-independent board, whose key committees are made up entirely of independent directors. As such, companies should attest to the independence of directors who serve on the Compensation, B-36 Nominating, and Audit committees. In any instance in which a director is not categorically independent, the basis for the independence determination should be clearly explained in the proxy statement. While the funds will generally support the board's nominees, the following factors will be taken into account in determining each fund's vote:

FACTORS FOR APPROVAL FACTORS AGAINST APPROVAL -------------------- Nominated slate Nominated slate results in board made up of a majority of non- results in board made independent directors. up of a majority of independent directors. All members of Audit, Audit, Nominating, and/or Compensation committees include non- Nominating, and independent members. Compensation committees are independent of management. Incumbent board member failed to attend at least 75% of meetings in the previous year. Actions of committee(s) on which nominee serves are inconsistent with other guidelines (e.g., excessive option grants, substantial non-audit fees, lack of board independence).

B. CONTESTED DIRECTOR ELECTIONS In the case of contested board elections, we will evaluate the nominees' qualifications, the performance of the incumbent board, as well as the rationale behind the dissidents' campaign, to determine the outcome that we believe will maximize shareholder value. C. CLASSIFIED BOARDS The funds will generally support proposals to declassify existing boards (whether proposed by management or shareholders), and will block efforts by companies to adopt classified board structures in which only part of the board is elected each year. II. APPROVAL OF INDEPENDENT AUDITORS The relationship between the company and its auditors should be limited primarily to the audit, although it may include certain closely related activities that do not, in the aggregate, raise any appearance of impaired independence. The funds will generally support management's recommendation for the ratification of the auditor, except in instances in which audit and audit-related fees make up less than 50% of the total fees paid by the company to the audit firm. We will evaluate on a case-by-case basis instances in which the audit firm has a substantial non-audit relationship with the company (regardless of its size relative to the audit fee) to determine whether independence has been compromised. III. COMPENSATION ISSUES A. STOCK-BASED COMPENSATION PLANS Appropriately designed stock-based compensation plans, administered by an independent committee of the board and approved by shareholders, can be an effective way to align the interests of long-term shareholders with the interests of management, employees, and directors. The funds oppose plans that substantially dilute their ownership interest in the company, provide participants with excessive awards, or have inherently objectionable structural features. An independent compensation committee should have significant latitude to deliver varied compensation to motivate the company's employees. However, we will evaluate compensation proposals in the context of several factors (a company's industry, market capitalization, competitors for talent, etc.) to determine whether a particular plan or proposal balances the perspectives of employees and the company's other shareholders. We will evaluate each proposal on a case-by-case basis, taking all material facts and circumstances into account. B-37 The following factors will be among those considered in evaluating these proposals.

FACTORS FOR APPROVAL FACTORS AGAINST APPROVAL -------------------- Company requires Total potential dilution (including all stock-based plans) exceeds 15% of senior executives to shares outstanding. hold a minimum amount of company stock (frequently expressed as a multiple of salary). Company requires stock Annual option grants have exceeded 2% of shares outstanding. acquired through option exercise to be held for a certain period of time. Compensation program Plan permits repricing or replacement of options without includes shareholder approval. performance-vesting awards, indexed options, or other performance-linked grants. Concentration of Plan provides for the issuance of reload options. option grants to senior executives is limited (indicating that the plan is very broad-based). Stock-based Plan contains automatic share replenishment (evergreen) feature. compensation is clearly used as a substitute for cash in delivering market-competitive total pay.

B. BONUS PLANS Bonus plans, which must be periodically submitted for shareholder approval to qualify for deductibility under Section 162(m) of the IRC, should have clearly defined performance criteria and maximum awards expressed in dollars. Bonus plans with awards that are excessive, in both absolute terms and relative to a comparative group, generally will not be supported. C. EMPLOYEE STOCK PURCHASE PLANS The funds will generally support the use of employee stock purchase plans to increase company stock ownership by employees, provided that shares purchased under the plan are acquired for no less than 85% of their market value and that shares reserved under the plan amount to less than 5% of the outstanding shares. D. EXECUTIVE SEVERANCE AGREEMENTS (GOLDEN PARACHUTES) While executives' incentives for continued employment should be more significant than severance benefits, there are instances--particularly in the event of a change in control--in which severance arrangements may be appropriate. Severance benefits triggered by a change in control that do not exceed three times an executive's salary and bonus may generally be approved by the compensation committee of the board without submission to shareholders. Any such arrangement under which the beneficiary receives more than three times salary and bonus--or where severance is guaranteed absent a change in control--should be submitted for shareholder approval. IV. CORPORATE STRUCTURE AND SHAREHOLDER RIGHTS The exercise of shareholder rights, in proportion to economic ownership, is a fundamental privilege of stock ownership that should not be unnecessarily limited. Such limits may be placed on shareholders' ability to act by corporate charter or by-law provisions, or by the adoption of certain takeover provisions. In general, the market for corporate control should be allowed to function without undue interference from these artificial barriers. The funds' positions on a number of the most commonly presented issues in this area are as follows: A. SHAREHOLDER RIGHTS PLANS (POISON PILLS) A company's adoption of a so-called poison pill effectively limits a potential acquirer's ability to buy a controlling interest without the approval of the target's board of directors. Such a plan, in conjunction with other takeover defenses, may serve to entrench incumbent management and directors. However, in other cases, a poison pill may force a suitor to negotiate with the board and result in the payment of a higher acquisition premium. In general, shareholders should be afforded the opportunity to approve shareholder rights plans within a year of their adoption. This provides the board with the ability to put a poison pill in place for legitimate defensive purposes, subject to B-38 subsequent approval by shareholders. In evaluating the approval of proposed shareholder rights plans, we will consider the following factors:

FACTORS FOR APPROVAL FACTORS AGAINST APPROVAL -------------------- Plan is relatively Plan is long term (>5 years). short-term (3-5 years). Plan requires Renewal of plan is automatic or does not require shareholder approval. shareholder approval for renewal. Plan incorporates Ownership trigger is less than 15%. review by a committee of independent directors at least every three years (so-called TIDE provisions). Plan includes Classified board. permitted-bid/qualified offer feature (chewable pill) that mandates a shareholder vote in certain situations. Ownership trigger is Board with limited independence. reasonable (15-20%). Highly independent, non-classified board.

B. CUMULATIVE VOTING The funds are generally opposed to cumulative voting under the premise that it allows shareholders a voice in director elections that is disproportionate to their economic investment in the corporation. C. SUPERMAJORITY VOTE REQUIREMENTS The funds support shareholders' ability to approve or reject matters presented for a vote based on a simple majority. Accordingly, the funds will support proposals to remove supermajority requirements and oppose proposals to impose them. D. RIGHT TO CALL MEETINGS AND ACT BY WRITTEN CONSENT The funds support shareholders' right to call special meetings of the board (for good cause and with ample representation) and to act by written consent. The funds will generally vote for proposals to grant these rights to shareholders and against proposals to abridge them. E. CONFIDENTIAL VOTING The integrity of the voting process is enhanced substantially when shareholders (both institutions and individuals) can vote without fear of coercion or retribution based on their votes. As such, the funds support proposals to provide confidential voting. F. DUAL CLASSES OF STOCK We are opposed to dual class capitalization structures that provide disparate voting rights to different groups of shareholders with similar economic investments. We will oppose the creation of separate classes with different voting rights and will support the dissolution of such classes. V. CORPORATE AND SOCIAL POLICY ISSUES Proposals in this category, initiated primarily by shareholders, typically request that the company disclose or amend certain business practices. The Board generally believes that these are "ordinary business matters" that are primarily the responsibility of management and should be evaluated and approved solely by the corporation's board of directors. Often, proposals may address concerns with which the Board philosophically agrees, but absent a compelling economic impact on shareholder value (e.g., proposals to require expensing of stock options), the funds will typically abstain from voting on these proposals. This reflects the belief that regardless of our philosophical perspective on the issue, these decisions should be the province of company management unless they have a significant, tangible impact on the value of a fund's investment and management is not responsive to the matter. VI. VOTING IN FOREIGN MARKETS Corporate governance standards, disclosure requirements, and voting mechanics vary greatly among the markets outside the United States in which the funds may invest. Each fund's votes will be used, where applicable, to advocate for improvements in governance and disclosure by each fund's portfolio companies. We will evaluate issues presented to shareholders for each fund's foreign holdings in the context with the guidelines described above, as well as local market B-39 standards and best practices. The funds will cast their votes in a manner believed to be philosophically consistent with these guidelines, while taking into account differing practices by market. In addition, there may be instances in which the funds elect not to vote, as described below. Many foreign markets require that securities be "blocked" or reregistered to vote at a company's meeting. Absent an issue of compelling economic importance, we will generally not subject the fund to the loss of liquidity imposed by these requirements. The costs of voting (e.g., custodian fees, vote agency fees) in foreign markets may be substantially higher than for U.S. holdings. As such, the fund may limit its voting on foreign holdings in instances where the issues presented are unlikely to have a material impact on shareholder value. VII. VOTING ON A FUND'S HOLDINGS OF OTHER VANGUARD FUNDS Certain Vanguard funds (owner funds) may, from time to time, own shares of other Vanguard funds (underlying funds). If an underlying fund submits a matter to a vote of its shareholders, votes for and against such matters on behalf of the owner funds will be cast in the same proportion as the votes of the other shareholders in the underlying fund. VIII. THE PROXY VOTING GROUP The Board has delegated the day-to-day operations of the funds' proxy voting process to the Proxy Voting Group, which the Committee oversees. While most votes will be determined, subject to the individual circumstances of each fund, by reference to the guidelines as separately adopted by each of the funds, there may be circumstances when the Proxy Voting Group will refer proxy issues to the Committee for consideration. In addition, at any time, the Board has the authority to vote proxies, when, in the Board's or the Committee's discretion, such action is warranted. The Proxy Voting Group performs the following functions: (1) managing proxy voting vendors; (2) reconciling share positions; (3) analyzing proxy proposals using factors described in the guidelines; (4) determining and addressing potential or actual conflicts of interest that may be presented by a particular proxy; and (5) voting proxies. The Proxy Voting Group also prepares periodic and special reports to the Board, and any proposed amendments to the procedures and guidelines. IX. THE PROXY OVERSIGHT COMMITTEE The Board, including a majority of the independent trustees, appoints the members of the Committee who are senior officers of Vanguard, a majority of whom are also officers of each Vanguard fund. The Committee does not include anyone whose primary duties include external client relationship management or sales. This clear separation between the proxy voting and client relationship functions is intended to eliminate any potential conflict of interest in the proxy voting process. In the unlikely event that a member of the Committee believes he or she might have a conflict of interest regarding a proxy vote, that member must recuse him or herself from the committee meeting at which the matter is addressed, and not participate in the voting decision. The Committee works with the Proxy Voting Group to provide reports and other guidance to the Board regarding proxy voting by the funds. The Committee has an obligation to conduct its meetings and exercise its decision-making authority subject to the fiduciary standards of good faith, fairness, and Vanguard's Code of Ethics. The Committee shall authorize proxy votes that the Committee determines, at its sole discretion, to be in the best interests of each fund's shareholders. In determining how to apply the guidelines to a particular factual situation, the Committee may not take into account any interest that would conflict with the interest of fund shareholders in maximizing the value of their investments. The Board may review these procedures and guidelines and modify them from time to time. The procedures and guidelines are available on Vanguard's website at www.vanguard.com. FINANCIAL STATEMENTS Vanguard Total Bond Market II Index Fund did not commence operations until January xx, 2009, and therefore has no financial statements as of the date of this SAI. The Fund's audited financial statements will be included in the Trust's Annual Report to Shareholders and will be incorporated by reference from the Annual Reports after the end of the Fund's first fiscal year. B-40 DESCRIPTION OF BOND RATINGS The following are excerpts from Moody's Investors Service, Inc.'s description of its four highest bond ratings: Aaa--Judged to be of the best quality. They carry the smallest degree of investment risk. Aa--Judged to be of high quality by all standards. Together with the Aaa group they make up what are generally known as high-grade bonds. A--Possess many favorable investment attributes and are to be considered as "upper-medium-grade obligations." Baa--Considered as medium-grade obligations (i.e., they are neither highly protected nor poorly secured). Interest payments and principal security appear adequate for the present but certain protective elements may be lacking or may be characteristically unreliable over any great length of time. Such bonds lack outstanding investment characteristics and, in fact, have speculative characteristics as well. Moody's also supplies numerical indicators (1, 2, and 3) to rating categories. The modifier 1 indicates that the security is in the higher end of its rating category; the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates a ranking toward the lower end of the category. The following are excerpts from Standard & Poor's description of its four highest bond ratings: AAA--Highest grade obligations. The capacity to pay interest and repay principal is extremely strong. AA--Also qualify as high-grade obligations. They have a strong capacity to pay interest and repay principal, and they differ from AAA issues only in small degree. A--Regarded as upper-medium-grade. They have a strong capacity to pay interest and repay principal although they are somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than debt in higher rated categories. BBB--Regarded as having an adequate capacity to pay interest and repay principal. Whereas they normally exhibit adequate protection parameters, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity to pay interest and repay principal for debt in this category than in higher rated categories. This group is the lowest that qualifies for commercial bank investment. Standard & Poor's applies indicators ("+" or "-" or no character) to its rating categories. The indicators show relative standing within the major rating categories. B-41 "FTSE(R)" and "FTSE4Good(TM)" are trademarks jointly owned by the London Stock Exchange plc and The Financial Times Limited and are used by FTSE International Limited under license. "GEIS" and "All-World" are trademarks of FTSE International Limited. The FTSE4Good US Select Index, FTSE Global Equity Index Series (GEIS), FTSE All-World Index, FTSE All-World ex US Index, and FTSE High Dividend Yield Index are calculated by FTSE International Limited. FTSE International Limited does not sponsor, endorse, or promote the fund; is not in any way connected to it; and does not accept any liability in relation to its issue, operation, and trading. The funds or securities referred to herein are not sponsored, endorsed, or promoted by MSCI, and MSCI bears no liability with respect to any such funds or securities. For any such funds or securities, the prospectus or the Statement of Additional Information contains a more detailed description of the limited relationship MSCI has with The Vanguard Group and any related funds. Russell is a trademark of The Frank Russell Company. Standard & Poor's(R), S&P(R), S&P 500(R), Standard & Poor's 500, and 500 are trademarks of The McGraw-Hill Companies, Inc., and have been licensed for use by The Vanguard Group, Inc. Vanguard mutual funds are not sponsored, endorsed, sold, or promoted by Standard & Poor's, and Standard & Poor's makes no representation regarding the advisability of investing in the funds. Vanguard ETFs are not sponsored, endorsed, sold, or promoted by Barclays Capital. Barclays Capital makes no representation or warranty, express or implied, to the owners of Vanguard ETFs or any member of the public regarding the advisability of investing in securities generally or in Vanguard ETFs particularly or the ability of the Barclays Capital Index to track general bond market performance. Barclays Capital hereby expressly disclaims all warranties of merchantability and fitness for a particular purpose with respect to the Barclays Capital index and any data included therein. Barclays Capital's only relationship to Vanguard and Vanguard ETFs is the licensing of the Barclays Capital Index which is determined, composed, and calculated by Barclays Capital without regard to Vanguard or the Vanguard ETFs. Barclays Capital is not responsible for and has not participated in the determination of the timing of, prices of, or quantities of Vanguard ETFs to be issued. CFA(R) and Chartered Financial Analyst(R) are trademarks owned by CFA Institute. SAI635 012009 B-42 PART C VANGUARD BOND INDEX FUNDS OTHER INFORMATION ITEM 23. EXHIBITS (a) Articles of Incorporation, Amended and Restated Agreement and Declaration of Trust, is filed herewith. (b) By-Laws, are filed herewith. (c) Instruments Defining Rights of Security Holders, reference is made to Articles III and V of the Registrant's Amended and Restated Agreement and Declaration of Trust, refer to Exhibit (a) above. (d) Investment Advisory Contract, The Vanguard Group, Inc., provides investment advisory services to the Funds at cost pursuant to the Amended and Restated Funds' Service Agreement, refer to Exhibit (h) below. (e) Underwriting Contracts, not applicable. (f) Bonus or Profit Sharing Contracts, reference is made to the section entitled "Management of the Funds" in Part B of this Registration Statement. (g) Custodian Agreement, to be filed by amendment. (h) Other Material Contracts, Fourth Amended and Restated Funds' Service Agreement, filed on April 22, 2008, Post-Effective Amendment No. 48; and form of Authorized Participant Agreement, filed on April 22, 2008, Post-Effective Amendment No. 48, are hereby incorporated by reference. (i) Legal Opinion, not applicable. (j) Other Opinion, Consent of an Independent Registered Public Accounting Firm, to be filed by amendment. (k) Omitted Financial Statements, not applicable. (l) Initial Capital Agreements, not applicable. (m) Rule 12b-1 Plan, not applicable. (n) Rule 18f-3 Plan, is filed herewith. (o) Reserved. (p) Code of Ethics, for The Vanguard Group, Inc., filed on January 17, 2007, Post-Effective Amendment No. 43, is hereby incorporated by reference. ITEM 24. PERSONS CONTROLLED BY OR UNDER COMMON CONTROL WITH REGISTRANT Registrant is not controlled by or under common control with any person. ITEM 25. INDEMNIFICATION The Registrant's organizational documents contain provisions indemnifying Trustees and officers against liability incurred in their official capacity. Article VII, Section 2 of the Amended and Restated Agreement and Declaration of Trust provides that the Registrant may indemnify and hold harmless each and every Trustee and officer from and against any and all claims, demands, costs, losses, expenses, and damages whatsoever arising out of or related to the performance of his or her duties as a Trustee or officer. However, this provision does not cover any liability to which a Trustee or officer would otherwise be subject by reason of willful misfeasance, bad faith, gross negligence, or reckless disregard of the duties involved in the conduct of his or her office. Article VI of the By-Laws generally provides that the Registrant shall indemnify its Trustees and officers from any liability arising out of their past or present service in that capacity. Among other things, this provision excludes any liability arising by reason of willful misfeasance, bad faith, gross negligence, or the reckless disregard of the duties involved in the conduct of the Trustee's or officer's office with the Registrant. C-2 ITEM 26. BUSINESS AND OTHER CONNECTIONS OF INVESTMENT ADVISER The Vanguard Group, Inc. ("Vanguard"), is an investment adviser registered under the Advisers Act. The list required by this Item 26 of officers and directors of Vanguard, together with any information as to any business, profession, vocation, or employment of a substantial nature engaged in by such officers and directors during the past two years, is incorporated herein by reference from Schedules B and D of Form ADV filed by Vanguard pursuant to the Advisers Act (SEC File No. 801-11953). ITEM 27. PRINCIPAL UNDERWRITERS (a) Vanguard Marketing Corporation, a wholly-owned subsidiary of The Vanguard Group, Inc., is the principal underwriter of each fund within the Vanguard group of investment companies, a family of 37 investment companies with more than 150 funds. (b) The principal business address of each named director and officer of Vanguard Marketing Corporation is 100 Vanguard Boulevard, Malvern, PA 19355.

Name Positions and Office with Underwriter Positions and Office with Funds ---- ------------------------------------- ------------------------------- R. Gregory Barton Director and Senior Vice President None Mortimer J. Buckley Director and Senior Vice President None F. William McNabb III Chairman and Director Chief Executive Officer and President Michael S. Miller Director and Managing Director None George U. Sauter Director None Heidi Stam Director and Senior Vice President Secretary Richard D. Carpenter Treasurer None David L. Cermak Principal None Joseph Colaizzo Financial and Operations Principal and Assistant None Treasurer Michael L. Kimmel Secretary None Sean P. Hagerty Principal None John C. Heywood Principal None Steve Holman Principal None Jack T. Wagner Assistant Treasurer None Jennifer M. Halliday Assistant Treasurer None Brian P. McCarthy Senior Registered Options Principal None Deborah McCracken Assistant Secretary None Miranda O'Keefe Compliance Registered Options Principal None Joseph F. Miele Registered Municipal Securities Principal None Scott M. Bishop Registered Municipal Securities Principal None --------------- Bradley J. Sacco Registered Municipal Securities Principal None ---------------- Jane K. Myer Principal None Pauline C. Scalvino Chief Compliance Officer Chief Compliance officer

(c) Not applicable. C-3 ITEM 28. LOCATION OF ACCOUNTS AND RECORDS The books, accounts, and other documents required by Section 31(a) of the Investment Company Act and the rules promulgated thereunder will be maintained at the offices of Registrant; Registrant's Transfer Agent, The Vanguard Group, Inc., 100 Vanguard Boulevard, Malvern, PA 19355; and the Registrant's Custodian, JPMorgan Chase Bank, 270 Park Avenue, New York, NY 10017-2070 ITEM 29. MANAGEMENT SERVICES Other than as set forth in the section entitled "Management of the Funds" in Part B of this Registration Statement, the Registrant is not a party to any management-related service contract. ITEM 30. UNDERTAKINGS Not applicable. C-4 SIGNATURES Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the Town of Valley Forge and the Commonwealth of Pennsylvania, on the 24th day of December, 2008. VANGUARD BOND INDEX FUNDS BY:______/s/ F. William McNabb III* F. WILLIAM MCNABB III CHIEF EXECUTIVE OFFICER AND PRESIDENT Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment to the Registration Statement has been signed below by the following persons in the capacities and on the date indicated:

/S/ JOHN J. BRENNAN* Chairman and Trustee December 24, 2008 ------------------------------ John J. Brennan /S/ F. WILLIAM MCNABB III* Chief Executive Officer December 24, 2008 ------------------------------ and President F. William McNabb III /S/ CHARLES D. ELLIS* Trustee December 24, 2008 ------------------------------ Charles D. Ellis /S/ EMERSON U. FULLWOOD* Trustee December 24, 2008 ------------------------------ Emerson U. Fullwood /S/ RAJIV L. GUPTA* Trustee December 24, 2008 ------------------------------ Rajiv L. Gupta /S/ AMY GUTMANN* Trustee December 24, 2008 ------------------------------ Amy Gutmann /S/ JOANN HEFFERNAN HEISEN* Trustee December 24, 2008 ------------------------------ JoAnn Heffernan Heisen /S/ ANDRE F. PEROLD* Trustee December 24, 2008 ------------------------------ Andre F. Perold /S/ ALFRED M. RANKIN, JR.* Trustee December 24, 2008 ------------------------------ Alfred M. Rankin, Jr. /S/ J. LAWRENCE WILSON* Trustee December 24, 2008 ------------------------------ J. Lawrence Wilson /S/ THOMAS J. HIGGINS* Chief Financial Officer December 24, 2008 ------------------------------ Thomas J. Higgins

*By: /s/ Heidi Stam -------------- Heidi Stam, pursuant to a Power of Attorney filed on January 18, 2008, see File Number 2-29601. Incorporated by Reference; and pursuant to a Power of Attorney file don September 26, 2008, see File No. 2-47371. C-5 INDEX TO EXHIBITS Articles of Incorporation, Amended and Restated Agreement and Declaration of Trust. . . . . . . . . . . . . . . . . . . . . . . . . Ex-99.A By-Laws. . . . . . . . . . . . . . . . . . . . . . . . Ex-99.B Rule 18f-3 Plan. . . . . . . . . . . . . . . . . . . . Ex-99.N C-6