| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | -295.4 | -241.8 | -202.2 | -83.9 | -32.8 | -31.2 | -26.4 | -6.8 |
| Depreciation and amortization | 0.5 | 0.4 | 0.5 | 0.1 | 0.1 | 0.1 | | |
| Stock-based compensation | 31.6 | 26.9 | 20.7 | 22.8 | 13.5 | 3.3 | 7.9 | |
| Change in working capital [+] | 97.1 | 109.1 | 48.4 | 42.6 | 14.9 | 5.5 | 8.6 | 2.1 |
| Accounts receivable | | | | | | | | 0.0 |
| Other current assets | -1.3 | -0.3 | 0.1 | 0.3 | -1.0 | 0.5 | 1.3 | -0.1 |
| Accounts payable | 2.5 | 20.4 | -0.2 | -1.3 | 0.6 | 0.9 | -0.1 | 0.1 |
| Accrued expenses | 36.4 | 9.8 | 21.6 | 16.8 | -2.2 | 4.1 | -2.3 | 0.0 |
| Other | 59.5 | 79.3 | 26.8 | 26.8 | 17.5 | | 9.8 | 2.0 |
| Other operating activities | -58.6 | -78.5 | -24.9 | -23.2 | -21.2 | | -7.8 | 1.6 |
| Cash from operations | -224.9 | -183.9 | -157.6 | -41.6 | -25.5 | -22.3 | -17.6 | -3.1 |
| |
| Capital expenditures [+] | -0.2 | -0.2 | -0.3 | -0.2 | 0.0 | -0.1 | 0.0 | 0.0 |
| Purchases of property and equipment | -0.2 | -0.2 | -0.3 | -0.2 | 0.0 | -0.1 | 0.0 | |
| Sales of property and equipment | | | | | | | 0.7 | |
| Sales of short-term investments, net [+] | 206.9 | -4.8 | 160.1 | 30.9 | -380.1 | -21.9 | 15.4 | |
| Purchases of short-term investments | -143.5 | -394.1 | -329.3 | -619.3 | -614.4 | -70.2 | -10.7 | |
| Sales of short-term investments | 350.4 | 389.3 | 489.5 | 650.2 | 234.3 | 48.3 | 26.1 | |
| Other cash from investing | | | | | | | 5.9 | |
| Cash from investing | 206.7 | -5.1 | 159.8 | 30.7 | -380.1 | -22.0 | 22.0 | 0.0 |
| |
| Issuance of common stock, net | | | | | | | | 0.0 |
| Financing costs | -0.9 | | | | | | | |
| Other cash from financing | 312.6 | 171.2 | 5.1 | 0.2 | 314.3 | 173.8 | 14.5 | 3.3 |
| Cash from financing | 313.5 | 171.2 | 5.1 | 0.2 | 314.3 | 173.8 | 14.5 | 3.3 |
| |
| Free cash flow | -225.1 | -184.1 | -157.9 | -41.8 | -25.5 | -22.4 | -17.6 | -3.1 |
| Per share (diluted) | ($13.13) | ($11.14) | ($10.22) | ($2.71) | ($1.73) | ($1.83) | ($3.38) | ($18.37) |
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