| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-05-19 | Dec-31-18 | Dec-05-18 | Dec-31-17 |
| | 10-K | 10-K | 10-K | 10-K | 8-K | 10-K | 8-K | 10-K |
| Net income | -81.4 | -58.4 | -34.4 | -20.2 | -20.2 | -18.2 | -18.2 | -22.5 |
| Depreciation and amortization [+] | 0.5 | 0.2 | 0.1 | 0.1 | | 0.0 | | 1.5 |
| Depreciation | 0.5 | 0.2 | 0.1 | 0.1 | | 0.0 | | 1.5 |
| Stock-based compensation | 10.5 | 7.0 | 0.7 | 0.9 | | 1.1 | | 1.6 |
| Change in working capital [+] | 9.6 | 2.8 | -0.9 | -2.6 | | 3.4 | | -0.7 |
| Other current assets | 0.1 | -0.7 | -0.4 | -1.0 | | -0.2 | | 0.0 |
| Accounts payable | | | | | | | | -0.8 |
| Accrued expenses | | | | | | | | 0.5 |
| Other | 9.5 | 3.5 | -0.5 | -1.6 | | 3.6 | | -0.4 |
| Other operating activities | 0.7 | 0.5 | 19.8 | 5.0 | | 2.0 | | -2.9 |
| Cash from operations | -60.1 | -47.9 | -14.7 | -16.9 | | -11.6 | | -23.0 |
| |
| Capital expenditures | -4.5 | -0.9 | -0.3 | 0.0 | | -0.1 | | -0.3 |
| Purchases of property and equipment | -4.5 | -0.9 | -0.3 | 0.0 | | -0.1 | | -0.3 |
| Purchases of short-term investments, net | -13.3 | | | | | | | -1.0 |
| Purchases of short-term investments | -13.3 | | | | | | | -8.0 |
| Sales of short-term investments | | | | | | | | 7.1 |
| Other cash from investing | 0.8 | -0.9 | | -2.3 | | | | |
| Cash from investing | -17.0 | -1.8 | -0.3 | -2.4 | | -0.1 | | -1.2 |
| |
| Issuance of common stock, net | 59.6 | 129.2 | 37.8 | 1.1 | | | | |
| Option exercises | 1.3 | 0.9 | | | | | | 0.0 |
| Financing costs | 0.0 | | 0.0 | -0.1 | | -0.1 | | |
| Other cash from financing | 1.2 | -7.6 | -6.2 | 23.8 | | 7.1 | | -0.6 |
| Cash from financing | 59.5 | 120.7 | 31.6 | 25.1 | | 7.2 | | -0.6 |
| |
| Free cash flow | -64.5 | -48.9 | -15.0 | -16.9 | | -11.7 | | -23.3 |
| Per share (diluted) | ($0.30) | ($0.25) | ($0.13) | ($1.22) | | ($2.36) | | ($1.03) |
| |
| Cash paid for interest | | | | | | | | 0.0 |
| Cash paid for income taxes | | | | | | | | 0.2 |