CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities:
Net loss	$ (22,631)	$ (12,006)
Adjustments to reconcile net loss to net cash flows from operating activities:
Depreciation and amortization expense	2,942	2,185
Stock-based compensation expense	29,443	26,481
Amortization of premiums and discounts on marketable securities	305	737
Amortization of debt issuance costs	36	0
Non-cash lease cost	3,120	3,420
Other	21	17
Changes in operating assets and liabilities:
Inventory	(3,348)	(3,703)
Accounts receivable	3,141	5,594
Other current assets	(164)	(793)
Accounts payable	(37)	(672)
Accrued expenses	(97)	(361)
Operating lease liabilities	(2,019)	(2,410)
Net cash provided by operating activities	10,712	18,489
Investing activities:
Purchases of investments	(43,950)	(49,375)
Sales and maturities of investments	35,944	50,913
Expenditures for property and equipment	(6,471)	(6,924)
Net cash used in investing activities	(14,477)	(5,386)
Financing activities:
Net proceeds from common stock issuance	3,040	9,701
Debt issuance costs	(1,076)	0
Payments on employee’s behalf for taxes related to vesting of restricted stock unit awards	(1,485)	(1,619)
Other	(39)	(252)
Net cash provided by financing activities	440	7,830
Net (decrease) increase in cash, cash equivalents, and restricted cash	(3,325)	20,933
Cash, cash equivalents, and restricted cash at beginning of period	68,541	33,831
Cash, cash equivalents, and restricted cash at end of period	65,216	54,764
Supplemental disclosure of cash flow information:
Right-of-use asset and lease liability recognized	137	45
Additions to property and equipment included in accounts payable	482	85
Restricted stock held for employee tax remittance included in accounts payable	0	57
Reconciliation of amounts within the condensed consolidated balance sheets:
Cash and cash equivalents	65,216	54,553
Restricted cash	0	211
Total cash, cash equivalents, and restricted cash at end of period	$ 65,216	$ 54,764