CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020
Operating Activities
Net loss	[1]	$ (82,406)	$ (78,530)
Adjustment to reconcile net loss to net cash used in operating activities:
Depreciation and amortization		6,093	1,092
Stock-based compensation		42,531	9,565
Accretion of unamortized discount and amortization of issuance costs		28	548
Fair value adjustment of financial instruments		0	20,808
Impairment charge		0	3,395
Deferred income taxes		(18,825)	0
Change in fair value of common stock warrant liabilities	[1]	(81,898)	0
Changes in operating assets and liabilities:
Accounts receivable, net		975	0
Prepaid expenses and other assets		(7,217)	(3,858)
Deferred offering costs		0	(13,507)
Accounts payable		(3,445)	3,078
Accrued professional fees		(3,989)	12,199
Loss contingency accrual		11,557	0
Other liabilities		33,270	15,466
Net cash used in operating activities		(103,326)	(29,744)
Investing Activities
Purchases of property and equipment, including internal-use software		(2,068)	(3,009)
Investment in non-marketable equity securities		(54,748)	0
Business combination, net of cash acquired		(83,987)	0
Net cash used in investing activities		(140,803)	(3,009)
Financing Activities
Payments of capital lease obligations		(946)	0
Payments for debt issuance costs		0	(201)
Payments under debt agreements		0	(10,000)
Proceeds from issuance of common stock in follow-on offering, net of underwriting commissions, and offering costs		402,139	0
Payments made towards offering costs		(13,221)	(653)
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs		0	76,617
Proceeds from exercise of stock options and issuance of common stock		3,166	673
Proceeds from exercise of common stock warrants, net of redemptions		130,571	0
Payments made to repurchase common stock and preferred stock		0	(2,450)
Net cash provided by financing activities		521,709	63,986
Net change in cash, cash equivalents and restricted cash		277,580	31,233
Cash, cash equivalents and restricted cash – beginning of year		265,648	28,548
Cash, cash equivalents and restricted cash – end of year		543,228	59,781
Cash paid during the period for:
Interest		161	800
Noncash investing and financing activities:
Issuance of common stock for business combination		67,051	0
Remeasurement of redeemable convertible preferred stock		0	865,952
Settlement of the Redeemable convertible Series E preferred stock forward contract liability		0	21,688
Deferred offering costs in accounts payable and accrued liabilities		0	12,795
Warrant liability reclassified to additional paid-in capital		$ 84,016	$ 0

[1] Retroactively restated for the reverse recapitalization as described in Notes 1 and 3.