Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities
Net loss	$ (104,631)	$ (90,353)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	9,505	4,724
Amortization of right-of-use assets and non-cash lease expense	1,933	1,792
Amortization of premiums and accretion of discounts on marketable securities	(2,176)	2,185
Stock-based compensation expense	37,990	28,481
Other	599	560
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(862)	2,082
Accrued compensation and benefits	(7,554)	(1,289)
Accounts payable and accrued liabilities	3,446	3,957
Operating lease liability and other	(569)	460
Net cash used in operating activities	(62,319)	(47,401)
Investing activities
Purchases of property and equipment	(28,012)	(39,294)
Proceeds from maturities of marketable securities	191,043	218,500
Proceeds from sales of marketable securities	1,477	13,113
Purchases of marketable securities	(100,422)	(183,892)
Net cash provided by investing activities	64,086	8,427
Financing activities
Proceeds from exercise of stock options	4,050	1,287
Net cash provided by financing activities	4,050	1,287
Net increase (decrease) in cash, cash equivalents and restricted cash	5,817	(37,687)
Cash, cash equivalents and restricted cash at beginning of period	252,916	338,223
Cash, cash equivalents and restricted cash at end of period	258,733	300,536
Supplemental disclosure of cash flow information
Purchases of property and equipment, not yet paid	$ 13,437	$ 7,754