| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | S-1/A |
| Net income | -131.1 | -98.6 | -39.2 | -23.8 | -10.2 | -9.2 |
| Depreciation and amortization | 1.8 | 0.5 | 0.2 | 0.1 | 0.1 | 0.1 |
| Stock-based compensation | 2.3 | 2.2 | 1.4 | 0.3 | 0.1 | 0.2 |
| Change in working capital [+] | 56.5 | 22.6 | -1.4 | 2.3 | 0.1 | -0.5 |
| Other current assets | 7.5 | -8.4 | -2.0 | -1.0 | 0.0 | |
| Accounts payable | 9.0 | 1.0 | 0.8 | 1.3 | -0.2 | -0.3 |
| Accrued expenses | 3.7 | 1.9 | -0.3 | 1.9 | 0.2 | |
| Other | 36.3 | 28.1 | 0.0 | 0.0 | 0.0 | -0.2 |
| Other operating activities | 23.1 | 13.3 | -0.5 | 4.1 | 1.7 | -0.2 |
| Cash from operations | -47.4 | -60.0 | -39.6 | -17.1 | -8.3 | -9.7 |
| |
| Capital expenditures | -2.7 | -1.3 | -1.0 | -0.1 | -0.2 | -0.1 |
| Purchases of property and equipment | -2.7 | -1.3 | -1.0 | -0.1 | -0.2 | -0.1 |
| Purchases of intangible assets | | -0.1 | | | | |
| Sales of short-term investments, net [+] | | | | | | 9.4 |
| Purchases of short-term investments | | | | | | -1.6 |
| Sales of short-term investments | | | | | | 11.0 |
| Other cash from investing | | | | | | 0.0 |
| Cash from investing | -2.7 | -1.4 | -1.0 | -0.1 | -0.2 | 9.2 |
| |
| Issuance of common stock, net | 60.4 | 2.9 | 46.3 | 43.0 | | |
| Option exercises | 0.4 | 0.1 | 0.2 | 0.1 | 0.0 | |
| Other cash from financing | 3.8 | 12.6 | 7.5 | 21.9 | 18.2 | 0.0 |
| Cash from financing | 63.8 | 15.5 | 53.5 | 64.8 | 18.2 | 0.0 |
| |
| Free cash flow | -50.1 | -61.3 | -40.6 | -17.2 | -8.5 | -9.8 |
| Per share (diluted) | ($1.14) | ($2.11) | ($1.48) | ($3.24) | ($11.40) | ($13.17) |
| |
| Cash paid for interest | 0.5 | 1.0 | 0.6 | 0.3 | 0.0 | |