CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating activities:
Net loss	$ (361,499)	$ (364,831)
Non-cash adjustments reconciling net loss to operating cash flows
Change in fair value on long-term investment	(1,100)	5,583
Depreciation and amortization expense	2,182	1,322
Amortization of premium and accretion of discounts on investments	(10,597)	1,457
Share-based compensation expense	86,360	81,589
Loss on disposal of property and equipment	0	(295)
Changes in operating assets and liabilities:
Accounts receivable, net	(9,658)	0
Inventory	(5,624)	0
Other current assets	923	(4,955)
Other long-term assets	(3,221)	(1,194)
Right-of-use asset	691	857
Lease liability	(822)	2,905
Accounts payable, accrued liabilities and other liabilities	(19,217)	(26,989)
Cash flows used in operating activities	(321,582)	(303,961)
Investing activities:
Purchases of short-term investments	(363,756)	(341,472)
Sales and maturities of short-term investments	575,430	496,834
Purchases of property and equipment	(991)	(2,801)
Cash flows provided by investing activities	210,683	152,561
Financing activities:
Proceeds from issuance of common stock under equity incentive plans	2,242	2,924
Proceeds from issuance of common stock from employee stock purchase plan	3,328	995
Cash flows provided by financing activities	5,570	3,919
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(65)	0
Decrease in cash, cash equivalents and restricted cash	(105,394)	(147,481)
Cash, cash equivalents and restricted cash, beginning of period	235,880	413,703
Cash, cash equivalents and restricted cash, end of period	130,486	266,222
Reconciliation of cash, cash equivalents and restricted cash, end of period:
Cash and cash equivalents	129,866	265,602
Restricted cash included in other long-term assets	620	620
Total cash, cash equivalents and restricted cash	130,486	266,222
Supplemental disclosures of non-cash investing activities:
Accrued capital expenditures	$ 0	$ 154