Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (22,078)	$ (49,825)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,685	1,361
Share in net loss of equity method investment	5,865
Stock-based compensation	19,049	7,108
Amortization of right-of-use assets	1,184	1,105
Accretion of discount on available-for-sale securities	1,022	289
Loss on write down of fixed assets		97
Amortization of debt issuance costs	357	478
Changes in operating assets and liabilities:
Accounts receivable	(18,277)	(3,334)
Inventory	(7,982)	(16,338)
Prepaid expenses and other current assets	(1,966)	(1,136)
Other assets	128	(161)
Accounts payable	2,168	(776)
Accrued and other current liabilities	13,011	2,841
Lease liabilities	(961)	(494)
Net cash used in operating activities	(5,795)	(58,785)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of available-for-sale securities	(75,566)	(16,020)
Proceeds from maturities of available-for-sale securities	134,700	72,000
Purchase of property and equipment	(9,616)	(9,846)
Net cash provided by investing activities	49,518	46,134
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments of offering costs		(179)
Proceed from issuance of common stock from public offering, net of issuance cost paid		83,368
Payments of taxes withheld on net settled vesting of restricted stock units	(8,337)	(862)
Principal payments of term loan		(1,111)
Net proceeds from term loan		3,265
Proceeds from stock option exercises	2,549	2,586
Proceeds from issuance of common stock under employee stock purchase plan	2,837	1,795
Net cash provided by (used in) financing activities	(2,951)	88,862
Net increase in cash, cash equivalents and restricted cash	40,772	76,211
Cash, cash equivalents and restricted cash at beginning of period	51,873	140,495
Cash, cash equivalents and restricted cash equivalents at end of period	92,645	216,706
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid	440	403
Income tax paid	114	22
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Right-of-use asset obtained in exchange for lease liability	5,406	121
Property and equipment purchases included in accounts payable and accrued liabilities	2,510	233
Equity method investment obtained in exchange for related party contract liability	12,273
Transfer of fixed assets to inventory	$ 270	$ 197