| In millions, except per share items | Jun-30-23 | Sep-30-22 | Jun-30-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 | Dec-31-20 |
| | 10-Q | 10-Q | 10-Q | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Net income | -14.1 | -12.0 | -10.9 | -7.7 | -8.7 | -6.7 | -5.2 | -5.8 |
| Depreciation and amortization [+] | 0.4 | 0.2 | 0.2 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Depreciation | 0.3 | 0.2 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Amortization of intangible assets | 0.1 | 0.1 | 0.1 | | 0.0 | | | |
| Asset impairment charges | | 0.2 | | | | | | |
| Stock-based compensation | 6.1 | 4.7 | 4.6 | 2.1 | 1.2 | 1.2 | 0.8 | 1.1 |
| Change in working capital [+] | -7.7 | -1.9 | -0.1 | -1.1 | 2.4 | 1.5 | -1.3 | -0.6 |
| Accounts receivable | 0.0 | 0.2 | | -0.2 | | 0.4 | -0.4 | |
| Inventories | -0.2 | -0.1 | -0.3 | | | | | |
| Other current assets | 0.1 | -0.1 | 0.5 | -0.2 | -0.2 | 0.2 | -1.2 | 0.0 |
| Accounts payable | -0.3 | 1.0 | -0.2 | -0.6 | 0.0 | 0.9 | 0.1 | -0.6 |
| Accrued expenses | -7.2 | -3.0 | -0.1 | -0.1 | 2.7 | -0.1 | 0.4 | 0.1 |
| Deferred revenues | | | | | | | -0.1 | -0.1 |
| Other operating activities | -1.8 | -0.5 | -0.7 | 0.3 | 0.1 | 0.1 | 0.1 | 0.0 |
| Cash from operations | -17.2 | -9.2 | -6.8 | -6.3 | -5.0 | -3.9 | -5.6 | -5.3 |
| |
| Capital expenditures | -0.8 | -1.0 | -0.3 | -0.4 | -0.6 | 0.0 | 0.0 | -0.1 |
| Purchases of property and equipment | -0.8 | -1.0 | -0.3 | -0.4 | -0.6 | 0.0 | 0.0 | -0.1 |
| Purchases of short-term investments, net | -8.9 | -32.6 | | | | | | |
| Purchases of short-term investments | -9.7 | -32.6 | | | | | | |
| Sales of short-term investments | 0.9 | | | | | | | |
| Other cash from investing | | 0.0 | 0.0 | | -0.1 | | | |
| Cash from investing | -9.7 | -33.6 | -0.3 | -0.4 | -0.7 | 0.0 | 0.0 | -0.1 |
| |
| Issuance of common stock, net | 5.8 | 0.2 | | 38.2 | 15.0 | 8.5 | 6.3 | -1.1 |
| Option exercises | 0.2 | | | 0.2 | 0.1 | | | 0.0 |
| Other cash from financing | 16.0 | -0.1 | -0.5 | 12.7 | -0.1 | -0.2 | 11.9 | 6.8 |
| Cash from financing | 21.6 | 0.1 | -0.5 | 50.7 | 14.8 | 8.3 | 18.2 | 5.7 |
| |
| Free cash flow | -17.9 | -10.2 | -7.1 | -6.8 | -5.6 | -3.9 | -5.6 | -5.4 |
| Per share (diluted) | ($0.57) | ($0.34) | ($0.24) | ($0.25) | ($0.23) | ($0.18) | ($0.31) | ($0.31) |
| |
| Cash paid for interest | 0.3 | 0.0 | 0.0 | 0.2 | 0.0 | 0.1 | 0.2 | 0.3 |
| Cash paid for income taxes | | 0.1 | | 0.1 | | | | |