CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities
Net loss	$ (32,818)	$ (31,337)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,571	1,488
Stock-based compensation	11,141	8,460
Non-cash operating lease cost	706	621
Changes in valuation of warrant investment	(402)
Loss on sale of available-for-sale securities		261
Unrealized gain on investments	(249)
Non-cash interest expense	481	237
Foreign currency remeasurement loss (gain)	197	(184)
Changes in operating assets and liabilities:
Accounts receivable	(2,134)	(739)
Inventories	(8,006)	962
Other assets	(2,580)	138
Accounts payable	7,389	(3,137)
Accrued liabilities and other non-current liabilities	(1,708)	(4,627)
Deferred product revenue	294	136
Net cash used in operating activities	(26,118)	(27,721)
Investing activities
Capital expenditures	(225)	(907)
Purchases of investments	(2,026)	(76,871)
Proceeds from maturities and sale of investments	33,500	25,998
Net cash provided by (used in) investing activities	31,249	(51,780)
Financing activities
Net proceeds from equity incentives	2,094	2,797
Net (offering costs) proceeds from public offerings	(292)	76,595
Net proceeds (payments) on revolving line of credit	813	(67)
Proceeds from loans	15,000
Net cash provided by financing activities	17,615	79,325
Effect of exchange rates on cash, cash equivalents, and restricted cash	(363)	115
Net increase (decrease) in cash, cash equivalents and restricted cash	22,383	(61)
Cash, cash equivalents and restricted cash, beginning of period	38,903	37,421
Cash, cash equivalents and restricted cash, end of period	$ 61,286	$ 37,360