Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities
Net loss	$ (130,851)	$ (76,797)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	298	225
Non-cash operating lease expense	559	502
Stock compensation expense	35,523	15,850
Equity investment loss	724	420
Changes in operating assets and liabilities
Prepaid expenses and other current assets	1,951	586
Other assets	22	(217)
Accounts payable	(1,233)	2,554
Accrued expenses	5,438	2,975
Lease liability	(190)	(697)
Other long-term liabilities	0	(33)
Net cash used in operating activities	(87,759)	(54,632)
Investing activities
Capital expenditures	(4,912)	(177)
Equity investments	(4,200)	0
Purchases of marketable securities	(67,953)	(140,897)
Proceeds from sale and maturity of debt securities	130,246	132,700
Net cash provided by (used in) investing activities	53,181	(8,374)
Financing activities
Treasury stock	(1,129)	0
Proceeds from stock option exercises	1,302	488
Net cash provided by financing activities	173	488
Net decrease in cash and cash equivalents	(34,405)	(62,518)
Cash and cash equivalents including Restricted cash, beginning of period	104,526	147,654
Cash and cash equivalents including Restricted cash, end of period	70,121	85,136
Non-cash investing activities
Right-of-use assets obtained in exchange for operating lease obligations	$ 5,580	$ 0