Condensed Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income (loss)	$ (22,856)	$ 11,029
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation expense	359	312
Stock-based compensation expense	2,578	425
Other	271	0
Changes in operating assets and liabilities:
Tax credit receivable	0	72
Accounts receivable	7,105	(24,710)
Prepaid expenses and other current assets	318	(883)
Other non-current assets	0	233
Accounts payable	665	1,176
Accrued liabilities	(2,092)	(424)
Other long-term liabilities	(13)	4
Net cash used in operating activities	(13,665)	(12,766)
Cash flows from investing activities
Purchase of short-term investments	(64,806)	(11,008)
Maturity of short-term investments	77,280	0
Accretion of short-term investments	0	(29)
Purchase of property and equipment	(242)	(336)
Net cash provided by/(used in) investing activities	12,232	(11,373)
Cash flows from financing activities
Proceeds from exercise of stock options	1,370	26
Payment of deferred offering costs	0	(364)
Net cash provided by financing activities	1,370	51,700
Net (decrease)/increase in cash and cash equivalents	(63)	27,561
Cash and cash equivalents at beginning of period	50,882	85,807
Cash and cash equivalents at end of period	50,819	113,368
Supplemental disclosures of noncash investing and financing activities:
Purchase of property and equipment in accounts payable and accrued liabilities	251	257
Reclassification of restricted stock awards from liabilities to common stock upon vesting	2	4
Deferred offering costs in accounts payable and accrued liabilities	0	792
Net unrealized gain on short-term investments	14	60
Series C Preferred Stock
Cash flows from financing activities
Proceeds from issuance of Series C preferred stock, net of issuance costs	$ 0	$ 52,038