Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (106,476)	$ (130,849)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	17,439	28,105
Impairment of other investments	13,001	12,923
Depreciation and amortization expense	9,925	10,089
Net amortization and accretion on marketable securities	(8,129)	(3,925)
Gain on marketable equity security	(149)	0
Change in fair value of success payment liabilities	(566)	(603)
Non-cash lease income	(979)	(816)
Loss on property and equipment disposals, net	15	430
Changes in operating assets and liabilities:
Prepaid expenses, other current assets and other assets	(246)	641
Accounts payable	(630)	2,449
Accrued liabilities and other current liabilities	(3,090)	(3,592)
Other non-current liabilities	(225)	(225)
Net cash used in operating activities	(80,110)	(85,373)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(361)	(2,466)
Purchases of marketable securities	(224,475)	(141,815)
Maturities of marketable securities	291,837	329,347
Net cash provided by investing activities	67,001	185,066
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from exercise of stock options	155	83
Proceeds from employee stock purchase plan	810	1,163
Taxes paid related to net share settlement of equity awards	(76)	(119)
Net cash provided by financing activities	889	1,127
Net (decrease) increase in cash, cash equivalents and restricted cash	(12,220)	100,820
Cash, cash equivalents and restricted cash at beginning of period	145,931	123,834
Cash, cash equivalents and restricted cash at end of period	133,711	224,654
Represented by:
Cash and cash equivalents	133,424	224,372
Restricted cash	287	282
Total	133,711	224,654
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for amounts included in the measurement of lease liabilities	5,551	5,215
Non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued liabilities	$ 50	$ 33