Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating activities
Net loss	$ (331,152)	$ (153,331)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	8,259	6,215
Expensed in-process research and development	35,604
Premium amortization and discount accretion on investment securities	5,707	3,333
(Gain) loss on investments	(58)
Stock-based compensation	84,797	34,406
Non-cash lease expense	8,106	5,819
Amortization of debt discount and issuance cost	917	149
Inventory reserve adjustments	726	(180)
Other non-cash benefits (charges)	133	(135)
Provision for credit losses	380	1,445
Loss on Debt Extinguishment		5,848
Accretion of Convertible Note		4,514
Changes in operating assets and liabilities
Accounts receivable	(32,232)	(17,940)
Inventory	(8,717)	(7,803)
Prepaid expenses and other current assets	(7,851)	(7,288)
Other assets	(550)	97
Accounts payable	183	(1,613)
Accrued compensation	4,960	6,362
Other accrued liabilities	34,845	16,362
Deferred revenue	(40,557)	(5,470)
Cash used in operating activities	(236,500)	(109,210)
Investing activities
Purchases of investments	(674,372)	(479,037)
Proceeds from sale of investments	77,563	11,500
Proceeds from maturity of investments	348,410	247,315
Purchases of property and equipment, net	(32,027)	(12,073)
Cash paid for acquisition of an asset	(4,271)
Cash used in investing activities	(284,697)	(232,295)
Financing activities
Proceeds from exercise of stock options	10,774	15,782
Proceeds from issuance of common stock under employee stock purchase plan	6,085	3,062
Proceeds from Convertible Note, net of issuance costs		278,316
Loan payment		(78,757)
Proceeds from public offering, net of issuance costs	550,814	270,650
Cash provided by financing activities	567,673	489,053
Net increase in cash, cash equivalents and restricted cash	46,476	147,548
Cash, cash equivalents and restricted cash, beginning of period	48,855	61,981
Cash, cash equivalents and restricted cash, end of period	95,331	209,529
Supplemental disclosure of cash flow information:
Cash paid for interest	3,690	3,137
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accruals	$ 4,957	$ 2,814