Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (115,178)	$ (20,436)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation of property and equipment	105	216
Amortization of discount/premium on investments	402	(277)
Share-based compensation	5,696	2,717
Fair value of common stock issued related to asset acquisition	43,445	0
Note payable related to asset acquisition	14,000	0
Gain on sale of investments	(2)	0
Lease-related amortization	292	(43)
Changes in operating assets and liabilities:
Accounts receivable	304	866
Prepaid expenses and other assets	(1,832)	809
Accounts payable and accrued liabilities	2,149	(2,546)
Net cash used in operating activities	(50,619)	(18,694)
Cash flows from investing activities:
Purchases of property and equipment	(188)	(11)
Purchases of short-term investments	(100,860)	(27,652)
Purchases of long-term investments	(7,554)	0
Proceeds from sales of short-term investments	2,007	1,498
Proceeds from maturities of short-term investments	23,850	80,652
Net cash (used in) provided by investing activities	(82,745)	54,487
Cash flows from financing activities:
Proceeds from exercise of stock options	3,648	578
Proceeds from employee stock purchase plan	330	229
Proceeds from issuance of common stock, net of commissions	107,842	0
Net cash provided by financing activities	111,820	807
Net (decrease) increase in cash and cash equivalents	(21,544)	36,600
Cash and cash equivalents:
Beginning of period	46,989	16,901
End of period	$ 25,445	$ 53,501