Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net (loss) income	$ (10,380)	$ 49,761
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	4,402	3,391
Amortization of premium on marketable securities	968	1,711
Stock-based compensation	23,408	17,643
Abandonment of capitalized intangible assets	1,047	310
Equity received in connection with sale of financial assets		(3,300)
Change in fair value of equity securities	9,974	(37,701)
Impairment on equity securities	138
Loss (gain) on disposal of assets	125	(4)
Changes in operating assets and liabilities:
Accounts receivable and contract asset	12,100	8,618
Interest receivable from marketable debt securities	(448)	496
Prepaid expenses and other assets	4,183	(4,930)
Accounts payable	1,746	(1,842)
Accrued expenses	(3,095)	(275)
Lease liabilities and ROU assets	7,911	(83)
Deferred revenue	(1,995)	(73,415)
Net cash provided by (used in) operating activities	50,084	(39,620)
Cash flows from investing activities
Purchase of marketable securities	(206,148)	(231,459)
Proceeds from sale of property and equipment		4
Purchase of intangible assets	(3,197)	(1,324)
Purchase of property and equipment	(14,443)	(4,234)
Proceeds from maturities and sale of marketable securities	76,390	221,752
Net cash used in investing activities	(147,398)	(15,261)
Cash flows from financing activities
Proceeds from issuance of common stock upon exercise of stock awards	2,047	6,242
Proceeds from issuance of common stock from Employee Stock Purchase Plan	1,197	937
Net cash provided by financing activities	3,244	7,179
Net decrease in cash and cash equivalents	(94,070)	(47,702)
Cash and cash equivalents, beginning of period	143,480	163,544
Cash and cash equivalents, end of period	49,410	115,842
Cash paid for:
Interest	9	9
Supplemental disclosures of non-cash investing activities
Unrealized loss on marketable securities	$ (7,435)	$ (90)