Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
OPERATING ACTIVITIES
Net loss	$ (33,045)	$ (11,610)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	12,470	1,387
Depreciation and amortization	1,042	701
Net amortization of premium on available-for-sale securities	412	100
Changes in operating assets and liabilities:
Accounts receivable, net	(896)	0
Related party receivables	(340)	0
Other receivables	(177)	(315)
Prepaid expenses and other current assets	(2,756)	78
Inventory	(2,119)	0
Other assets	(16)	(48)
Accounts payable	(644)	(82)
Deferred revenue	195	250
Deferred rent	391	269
Accrued expenses	241	(477)
Accrued research and development	94	(106)
Other noncurrent liabilities	(74)	0
Net cash used in operating activities	(25,222)	(9,853)
INVESTING ACTIVITIES
Purchases of property and equipment	(2,943)	(3,542)
Purchase of available-for-sale securities	(129,320)	(3,437)
Proceeds from maturities of available-for-sale securities	80,000	17,250
Net cash provided by (used in) investing activities	(52,263)	10,271
FINANCING ACTIVITIES
Proceeds from issuance of common stock upon follow-on public offering, net of issuance costs	102,959	0
Proceeds from return of profit	11,403	0
Repurchase of Class A common stock	(13)	(7)
Proceeds from stock option exercises including early exercised options	407	72
Proceeds from issuance of Series D-1 preferred stock, net of issuance costs	0	54,975
Net cash provided by financing activities	114,756	55,040
Net increase in cash, cash equivalents and restricted cash	37,271	55,458
Cash, cash equivalents and restricted cash, beginning of period	333,928	17,828
Cash, cash equivalents and restricted cash, end of period	371,199	73,286
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for income taxes	441	0
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Convertible preferred stock issuance costs included in accounts payable	0	79
Accounts Payable
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases included in balance sheet locations	246	76
Accrued Liabilities
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES
Property and equipment purchases included in balance sheet locations	$ 361	$ 3