Equity-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Stock Option Activity

A summary of stock option activity under the 2020 Stock Option and Grant Plan during the year ended December 31, 2021 is as follows (in thousands except share and per share data):

	Number of Options Outstanding			Weighted Average Strike Price per Option		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding at December 31, 2020		5,832,712		$	8.17		9.08	$	314,001
Granted		2,390,939			51.17
Exercised		(1,431,271	)		5.33
Forfeited		(553,198	)		23.76
Outstanding at December 31, 2021		6,239,182		$	23.91		8.56	$	246,933
Exercisable at December 31, 2021		1,928,457		$	12.99		8.18	$	97,387

Summary of Equity-Based Compensation Expense

The following table outlines equity-based compensation expense for stock options for the years ended December 31, 2021, 2020 and 2019:

	Year ending December 31,
	2021		2020		2019
Research and development	$	11,161	$	2,084	$	380
General and administrative		12,628		2,864		212
Total equity-based compensation	$	23,789	$	4,948	$	592

Summary of Weighted-Average Assumptions

The weighted-average assumptions that the Company used in Black-Scholes option pricing model to determine the grant date fair value of stock options granted to employees and non-employees for the years ended December 31, 2021, 2020 and 2019:

	Year ending December 31,
	2021			2020			2019
Expected term (in years)		5.87		6.09				6.49
Volatility		66	%		70	%		71	%
Risk-free interest rate		0.9	%		0.5	%		1.83	%
Dividend yield		0.00	%		0.00	%		0.00	%

Summary of Restricted Stock Activity

A summary of restricted stock activity under the 2018 Plan during the year ended December 31, 2021 is as follows:

	Number of Units Outstanding			Grant Date Fair Value per Share
Unvested at December 31, 2020		110,104		$	1.60
Granted		12,500			53.50
Vested		(84,859	)		9.25
Forfeited		—			—
Unvested at December 31, 2021		37,745		$	1.60

Stock Options

Summary of Equity-Based Compensation Expense

Total equity-based compensation expense recorded as research and development and general and administrative expenses for employees, directors, and non-employees during the years ended December 31, 2021, 2020 and 2019 is as follows (in thousands):

	Years ending December 31,
	2021		2020		2019
Research and development	$	11,731	$	2,305	$	688
General and administrative		13,241		2,885		508
Total equity-based compensation	$	24,972	$	5,190	$	1,196