The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
ALIBABA GROUP HLDG LTD SPONSORED ADS 01609W102 737 4,976 SH   SOLE   0 0 0
ALPHABET INC CAP STK CL A 02079K305 25,209 9,429 SH   DFND   0 0 0
ALPHABET INC CAP STK CL C 02079K107 105,922 39,741 SH   DFND   0 0 0
AMAZON COM INC COM 023135106 2,309 703 SH   DFND   0 0 0
AMETEK INC COM 031100100 95,023 766,249 SH   DFND   0 0 0
APPLE INC COM 037833100 1,618 11,438 SH   DFND   0 0 0
ARISTA NETWORKS INC COM 040413106 8,298 24,148 SH   SOLE   0 0 0
AUTOHOME INC SP ADS RP CL A 05278C107 17,303 368,701 SH   DFND   0 0 0
BANK OZK COM 06417N103 7,675 178,572 SH   DFND   0 0 0
BERKSHIRE HATHAWAY INC DEL CL A 084670108 3,291 8 SH   SOLE   0 0 0
BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 204,035 747,544 SH   DFND   0 0 0
BK OF AMERICA CORP COM 060505104 57,269 1,349,092 SH   DFND   0 0 0
BROOKFIELD ASSET MGMT INC CL A LTD VT SH 112585104 909 16,989 SH   DFND   0 0 0
CARMAX INC COM 143130102 148,380 1,159,579 SH   DFND   0 0 0
CGI INC CL A SUB VTG 12532H104 141 1,665 SH   DFND   0 0 0
CREDIT ACCEP CORP MICH COM 225310101 9,942 16,986 SH   DFND   0 0 0
DISNEY WALT CO COM 254687106 33,885 200,300 SH   DFND   0 0 0
EDWARDS LIFESCIENCES CORP COM 28176E108 45,527 402,150 SH   DFND   0 0 0
FACEBOOK INC CL A 30303M102 84,222 248,158 SH   DFND   0 0 0
FASTENAL CO COM 311900104 501 9,704 SH   DFND   0 0 0
FIRST REP BK SAN FRANCISCO C COM 33616C100 5,197 26,944 SH   DFND   0 0 0
FIVE BELOW INC COM 33829M101 58,959 333,458 SH   DFND   0 0 0
FORTUNE BRANDS HOME & SEC IN COM 34964C106 49,969 558,812 SH   DFND   0 0 0
HEALTHCARE SVCS GROUP INC COM 421906108 9,250 370,166 SH   DFND   0 0 0
HEICO CORP NEW CL A 422806208 70,581 595,976 SH   DFND   0 0 0
INTERCONTINENTAL EXCHANGE IN COM 45866F104 36,261 315,808 SH   DFND   0 0 0
II-VI INC COM 902104108 3,824 64,414 SH   SOLE   0 0 0
INTUITIVE SURGICAL INC COM NEW 46120E602 45 135 SH   DFND   0 0 0
ISHARES SILVER TR ISHARES 46428Q109 472 23,000 SH   SOLE   0 0 0
ISHARES US FINANCIALS ETF U.S. FINLS ETF 464287788 257 3,110 SH   DFND   0 0 0
ISHARES US HOME CONSTRUCT US HOME CONS ETF 464288752 242 3,661 SH   DFND   0 0 0
JPMORGAN CHASE & CO COM 46625H100 62,492 381,770 SH   DFND   0 0 0
KEYSIGHT TECHNOLOGIES INC COM 49338L103 70,707 430,380 SH   DFND   0 0 0
KNIGHT-SWIFT TRANSN HLDGS IN CL A 499049104 412 8,046 SH   DFND   0 0 0
LIBERTY BROADBAND CORP COM SER A 530307107 5,969 35,455 SH   SOLE   0 0 0
LILLY ELI & CO COM 532457108 100 432 SH   DFND   0 0 0
LITTELFUSE INC COM 537008104 757 2,770 SH   DFND   0 0 0
LULULEMON ATHLETICA INC COM 550021109 1,868 4,615 SH   DFND   0 0 0
M & T BK CORP COM 55261F104 699 4,683 SH   DFND   0 0 0
MARKEL CORP COM 570535104 88,693 74,212 SH   DFND   0 0 0
MASTERCARD INCORPORATED CL A 57636Q104 4,589 13,199 SH   DFND   0 0 0
MICROSOFT CORP COM 594918104 1,009 3,578 SH   DFND   0 0 0
NOVO-NORDISK A S ADR 670100205 595 6,200 SH   DFND   0 0 0
NVR INC COM 62944T105 73,714 15,376 SH   DFND   0 0 0
OLD DOMINION FREIGHT LINE IN COM 679580100 1,163 4,067 SH   DFND   0 0 0
PROGRESSIVE CORP COM 743315103 72,393 800,896 SH   DFND   0 0 0
RESMED INC COM 761152107 115 437 SH   DFND   0 0 0
RITCHIE BROS AUCTIONEERS COM 767744105 66 1,070 SH   DFND   0 0 0
ROPER TECHNOLOGIES INC COM 776696106 651 1,460 SH   DFND   0 0 0
SCHWAB CHARLES CORP COM 808513105 81,516 1,119,111 SH   DFND   0 0 0
SLEEP NUMBER CORP COM 83125X103 32,446 347,091 SH   DFND   0 0 0
SPDR S&P 500 ETF TR TR UNIT 78462F103 2,082 4,852 SH   DFND   0 0 0
SS&C TECHNOLOGIES HLDGS INC COM 78467J100 8,527 122,870 SH   DFND   0 0 0
STARBUCKS CORP COM 855244109 698 6,327 SH   DFND   0 0 0
TAIWAN SEMICONDUCTOR MFG LTD SPONSORED ADS 874039100 1,390 12,448 SH   DFND   0 0 0
TJX COS INC NEW COM 872540109 629 9,539 SH   DFND   0 0 0
UNITEDHEALTH GROUP INC COM 91324P102 1,493 3,820 SH   SOLE   0 0 0
VISA INC COM CL A 92826C839 73,744 331,063 SH   DFND   0 0 0
WAYFAIR INC CL A 94419L101 1,390 5,439 SH   SOLE   0 0 0