Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net loss	$ (186,337)	$ (106,299)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,075	466
Stock-based compensation	54,073	21,012
Amortization (accretion) of premium (discount) on marketable securities	(314)	25
Amortization of operating lease right-of-use asset	3,742	3,897
Amortization of issuance costs	26	26
Changes in assets and liabilities:
Prepaid expenses and other current assets	(2,165)	(431)
Other assets	10,235	(35)
Accounts payable	12,864	(5,753)
Accrued and other current liabilities	1,545	15,459
Operating lease liability	6,959	347
Net cash used in operating activities	(98,297)	(71,286)
Cash flows from investing activities
Purchase of property and equipment	(25,690)	(3,772)
Deposits on property and equipment	(8,785)	(16,962)
Purchase of marketable securities	(427,766)
Maturities of marketable securities	0	24,500
Net cash provided by (used in) investing activities	(462,241)	3,766
Cash flows from financing activities
Proceeds from issuance of common stock upon options exercise	1,680	3,711
Proceeds from issuance of common stock pursuant to employee stock purchase plans	64	305
Principal payments of tenant improvement allowance payable	(24)	(22)
Net cash provided by financing activities	1,720	3,994
Net increase (decrease) in cash, cash equivalents and restricted cash	(558,818)	(63,526)
Cash, cash equivalents and restricted cash, at beginning of period	737,834	950,720
Cash, cash equivalents and restricted cash, at end of period	179,016	887,194
Reconciliation of cash, cash equivalents and restricted cash to consolidated balance sheets
Cash and cash equivalents	172,692	880,870
Restricted cash	6,324	6,324
Cash, cash equivalents and restricted cash, at end of period	179,016	887,194
Supplemental disclosures of non-cash investing and financing information:
Operating lease right-of-use asset obtained in exchange for operating lease liability	74	498
Purchase of property and equipment under accounts payable and accruals	$ 9,718	$ 1,821