| 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 | -147.6 | -148.4 | -99.3 | -122.4 | -85.3 | -64.9 | -34.7 | -21.7 |
| Depreciation and amortization | 0.5 | 0.5 | 0.6 | 0.4 | 0.2 | 0.1 | 0.1 | 0.0 |
| Stock-based compensation | 20.6 | 22.3 | 18.8 | 16.4 | 10.2 | 3.4 | 1.4 | 0.4 |
| Change in working capital [+] | 31.2 | 18.8 | 19.7 | 6.1 | 0.6 | 6.1 | 3.6 | 7.1 |
| Accounts receivable | -5.4 | -5.5 | -0.2 | | | | | |
| Inventories | -12.7 | -3.5 | | | | | | |
| Other current assets | 7.2 | -3.4 | -5.5 | -0.2 | 0.1 | -0.3 | 0.2 | -0.8 |
| Accounts payable | 4.4 | -0.7 | -0.2 | 0.2 | -1.0 | 1.6 | 1.5 | |
| Accrued expenses | 1.2 | 3.3 | 1.7 | 6.0 | 1.4 | 4.7 | 1.9 | |
| Deferred revenues | 0.0 | 0.8 | 0.2 | | | | | |
| Other | 36.5 | 27.6 | 23.8 | | 0.0 | 0.0 | 0.0 | 7.8 |
| Other operating activities | -33.3 | -25.3 | -23.5 | | 0.0 | 4.8 | 4.5 | 0.4 |
| Cash from operations | -128.6 | -132.1 | -83.7 | -99.6 | -74.3 | -50.5 | -25.1 | -13.8 |
| |
| Capital expenditures [+] | -0.5 | 0.0 | 0.0 | -2.7 | -0.7 | -0.3 | -0.3 | -0.1 |
| Purchases of property and equipment | -0.5 | | | -2.7 | -0.7 | -0.3 | -0.3 | -0.1 |
| Sales of property and equipment | | | 0.2 | | | | | |
| Purchases of short-term investments, net | -50.0 | | | | | | | |
| Purchases of short-term investments | -65.0 | | | | | | | |
| Sales of short-term investments | 15.0 | | | | | | | |
| Cash from investing | -50.5 | 0.0 | 0.2 | -2.7 | -0.7 | -0.3 | -0.3 | -0.1 |
| |
| Issuance of common stock, net | 52.4 | 86.4 | | | 339.6 | 108.5 | | |
| Option exercises | 0.2 | 5.8 | 2.3 | 2.7 | 1.8 | 0.2 | 0.0 | 0.1 |
| Financing costs | | -1.4 | -0.6 | | | | | |
| Other cash from financing | 0.3 | 63.9 | 23.4 | 5.4 | 2.7 | -1.0 | 49.8 | 33.2 |
| Cash from financing | 52.5 | 145.9 | 21.7 | 2.7 | 340.5 | 107.3 | 49.8 | 33.2 |
| |
| Free cash flow | -129.1 | -132.1 | -83.7 | -102.3 | -75.0 | -50.8 | -25.4 | -13.9 |
| Per share (diluted) | ($2.96) | ($3.15) | ($2.21) | ($2.73) | ($2.25) | ($2.79) | ($17.08) | ($10.36) |
| |
| Cash paid for interest | 7.9 | 2.9 | 1.0 | | | | | |