Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income	$ (107,659)	$ (18,114)	$ (72,064)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,075	1,057	260
Stock-based compensation	67,211	5,831	8,028
Change in fair value of liabilities	(3,802)	3,101	(951)
Warrant expense in connection with Merger	154	0	0
Lease termination expense	0	754	0
Amortization of debt issuance costs	144	322	70
Net amortization on securities	2,166	325	(200)
Benefit for deferred taxes	(3,388)	0	0
Non-cash operating lease cost	1,510	0	0
Non-cash acquisition-related costs	1,182	0	0
Non-cash other	540	59	(158)
Changes in operating assets and liabilities:
Inventory	(9,628)	674	(522)
Prepaid expenses and other current assets	3,200	(645)	(2,436)
Other long-term assets	(58)	8	(755)
Accounts payable	9,853	826	(6,075)
Accrued liabilities	197	2,423	(276)
Deferred revenue	1,412	519	212
Operating lease liabilities	(1,521)	0	0
Other long-term liabilities	0	381	0
Net cash used in operating activities	(34,412)	(2,479)	(74,867)
Investing activities
Purchases of investments	(266,633)	(95,008)	(42,012)
Maturities of investments	158,375	47,990	4,500
Proceeds from sales of investments	3,465	11,550	0
Acquisition of businesses, net of cash acquired	(46,468)	0	0
Investment in website development and internal-use software	(4,175)	(2,496)	(1,479)
Purchases of property, equipment, and intangible assets	(832)	(1,737)	(308)
Net cash used in investing activities	(156,268)	(39,701)	(39,299)
Financing activities
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	0	51,900	102,566
Payments for debt issuance costs	0	0	(377)
Pre-closing stock repurchase	(22,027)	0	0
Proceeds from issuance of common stock upon Merger	197,686	0	0
Proceeds from PIPE	75,000	0	0
Payments for transaction costs related to securities issuances	(12,851)	(3,356)	0
Proceeds from repayment of promissory notes associated with vested and unvested shares	1,193	0	0
Proceeds from exercise of Series C preferred stock warrants	0	29	0
Proceeds from exercise of Class A common stock warrants, net of redemption payments	787	561	0
Proceeds from exercise of vested and unvested stock options, net of repurchases and cancelations	1,253	123	44
Borrowings of principal on term loan	0	0	2,136
Repayments of principal on term loan	0	(1,515)	(9,051)
Payments for taxes related to net share settlement of equity awards	(5,998)	0	0
Net cash provided by financing activities	235,043	47,742	95,318
Foreign currency effect on cash and cash equivalents	(73)	(9)	(5)
Increase (decrease) in cash, cash equivalents, and restricted cash	44,290	5,553	(18,853)
Cash, cash equivalents, and restricted cash at beginning of period	28,350	22,797	41,650
Cash, cash equivalents, and restricted cash at end of period	72,640	28,350	22,797
Supplemental disclosures of cash flow information
Cash paid for taxes	338	221	139
Cash paid for interest	0	10	361
Non-cash investing and financing activities
Redeemable Class A common stock reclassification	0	0	4,500
Warrants issued for debt issuance costs	0	0	133
Expiration of Class A common stock redemption right	0	4,500	0
Exercise of convertible preferred stock warrants	0	11,292	0
Recapitalization of redeemable convertible preferred stock from pre-closing stock repurchase	125	0	0
Conversion of redeemable convertible preferred stock to common stock	249,837	0	0
Assumption of Merger warrants liability	51,814	0	0
Redemption/exercise of Class A common stock warrants	37,834	0	0
Conversion of Series D preferred stock warrants to Class A common warrants	1,160	0	0
Vesting of early-exercised stock options, net of cancelations	227	31	12
Common stock issued, contingent consideration, and liabilities assumed in acquisition of businesses	$ 99,958	$ 0	$ 0