Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Operating activities
Net loss	$ (51,404)	$ (6,033)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	394	180
Stock-based compensation	34,230	1,404
Change in fair value of warrant liabilities	2,681	(71)
Warrant expense in connection with Merger	154	0
Amortization of debt issuance costs	144	84
Noncash other	452	(16)
Changes in operating assets and liabilities:
Inventory	(980)	(2,000)
Prepaid expenses and other current assets	(7,147)	(471)
Other long-term assets	(58)	733
Accounts payable	5,117	674
Accrued liabilities	1,114	199
Deferred revenue	(648)	126
Deferred rent	3	0
Net cash used in operating activities	(15,948)	(5,191)
Investing activities
Purchases of investments	(172,021)	(17,642)
Maturities of investments	9,500	19,200
Proceeds from sales of investments	0	6,400
Investment in website development and internal-use software	(740)	(452)
Purchases of property, equipment, and intangible assets	(63)	(273)
Net cash (used in)/provided by investing activities	(163,324)	7,233
Financing activities
Proceeds from issuance of redeemable convertible preferred stock	0	31,600
Payments of stock issuance costs	(12,794)	(89)
Pre-closing stock repurchase	(22,027)	0
Proceeds from issuance of common stock, recapitalization	197,686	0
Proceeds from PIPE	75,000	0
Repayment of promissory notes associated with vested and unvested shares	1,193	0
Proceeds from exercise of Class A common stock warrants	807	0
Proceeds from exercise of vested and unvested stock options, net of repurchases	80	(18)
Repayments of principal on term loan	0	(1,158)
Net cash provided by financing activities	239,945	30,335
Foreign currency effect on cash and cash equivalents	2	(9)
Increase in cash, cash equivalents, and restricted cash	60,675	32,368
Cash, cash equivalents, and restricted cash at beginning of the year	28,350	22,797	$ 22,797
Cash, cash equivalents, and restricted cash at end of the three-month period	89,025	55,165	$ 28,350
Supplemental disclosures of cash flow information
Cash paid for taxes	59	69
Cash paid for interest	0	8
Noncash investing and financing activities
Recapitalization of redeemable convertible preferred stock from pre-closing stock repurchase	125	0
Conversion of redeemable convertible preferred stock to common stock	249,837	0
Assumption of Merger warrants liability	51,814	0
Exercise of Private Placement Warrants and Public Warrants	20,871	0
Reclassification of deferred transaction costs	3,929	0
Conversion of Series D preferred stock warrants to Class A common warrants	1,160	0
Change in transaction costs payable	511	0
Vesting of early exercised stock options	54	11
Expiration of Class A common stock redemption right	$ 0	$ 4,500