STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows used in operating activities:
Net loss	$ (78,852)	$ (37,679)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	625	409
Noncash lease expense	928
Stock-based compensation	15,156	2,461
Amortization of premium and discount on marketable securities, net	356
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(2,532)	(1,924)
Accounts payable	7,834	1,931
Accrued expenses and other liabilities	(393)	3,472
Operating lease liabilities	(951)
Net cash used in operating activities	(57,829)	(31,330)
Cash flows used in investing activities:
Purchases of marketable securities	(259,973)
Purchases of property and equipment	(2,026)	(292)
Net cash used in investing activities	(261,999)	(292)
Cash flows provided by financing activities:
Proceeds from the issuance of common stock upon initial public offering, net of offering costs		167,929
Proceeds from the sale of common stock, net of offering costs	161,424
Payment of capital lease obligation		(258)
Proceeds from the exercise of stock options	1,519	96
Net cash provided by financing activities	162,943	247,535
Net (decrease) increase in cash and cash equivalents	(156,885)	215,913
Cash and cash equivalents at beginning of period	218,309	18,879
Cash and cash equivalents at end of period	61,424	234,792
Supplemental disclosures:
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	567
Property and equipment in accounts payable	97	90
Unrealized gain (loss) on marketable securities	$ (176)
Offering costs in accounts payable		1,079
Offering costs in accrued expenses and other current liabilities		220
Series B Convertible Preferred Stock
Cash flows provided by financing activities:
Proceeds from the sale of convertible preferred stock, net of offering costs		29,942
Series C Convertible Preferred Stock
Cash flows provided by financing activities:
Proceeds from the sale of convertible preferred stock, net of offering costs		$ 49,826