Stock Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Schedule of Total Stock-based Compensation Expense Recognized

In connection with all stock-based payments, total stock-based compensation expense recognized was as follows:

	Year Ended December 31,
	2021		2020		2019
Research and development expenses	$	24,922	$	14,691	$	2,687
General and administrative expenses		23,532		17,269		1,769
	$	48,454	$	31,960	$	4,456

Schedule of Estimated Fair Value of Stock Options

The following table summarizes the assumptions used in calculating the fair value of the time-based stock options granted.

	Year Ended December 31,
	2021	2020	2019
Risk-free interest rate	0.6 - 1.6%	0.4 - 1.8%	1.54 - 2.5%
Expected term (in years)	6.3	6.25	6.3
Expected volatility	74.7 - 76.6%	73.5 - 77.6%	72.8 - 73.5%
Expected dividend yield	0%	0%	0%

Schedule of Restricted Stock Units Activity

The following table summarizes activity for RSUs under the 2020 Stock Plan for the year ended December 31, 2021:

	Number of Shares Underlying RSUs			Weighted- Average Grant Date Fair Value
Unvested at December 31, 2020		—		$	—
Granted		782,299			33.39
Vested		(75,875	)		34.54
Cancelled		(15,219	)		37.63
Unvested at December 31, 2021		691,205			34.51

Schedule of Estimated Fair Value of Employee Stock Purchase Plan

In connection therewith, the Company recognized $0.6 million in stock-based compensation expense over the offering period ended December 31, 2021, based on the following assumptions underlying the Black-Scholes option pricing model to estimate the fair value of the option component of the shares purchased under the ESPP.

	Year Ended December 31,
	2021
Risk-free interest rate	0.1%
Expected term (in years)	0.5
Expected volatility	65.1%
Expected dividend yield	0%

Time-Based Stock Options [Member]

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Schedule of Stock Option Activity

The following table summarizes activity for time-based stock options under the 2016 Stock Plan and the 2020 Stock Plan for the year ended December 31, 2021:

	Number of Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Term (years)		Aggregate Intrinsic Value
Outstanding at December 31, 2020		5,756,578		$	7.59		7.63	$	196,634
Granted		2,363,676			34.20
Exercised		(960,768	)		4.82
Cancelled		(253,119	)		15.37
Outstanding at December 31, 2021		6,906,367		$	16.80		7.90	$	111,021
Vested at December 31, 2021		2,971,597		$	8.24		7.09	$	68,991
Unvested at December 31, 2021		3,934,770		$	23.27		8.51	$	42,029

Performance-Based Stock Options [Member]

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Schedule of Stock Option Activity

The following table summarizes activity for performance-based stock options for the year ended December 31, 2021:

	Number of Stock Options			Weighted- Average Exercise Price		Weighted- Average Remaining Term (years)		Aggregate Intrinsic Value
Outstanding at December 31, 2020		1,940,480		$	5.22		8.58	$	70,517
Granted		12,073			33.39
Exercised		(35,768	)		5.22
Cancelled		(103,525	)		5.22
Outstanding at December 31, 2021		1,813,260		$	5.41		8.11	$	45,912
Vested at December 31, 2021		499,464		$	5.22		8.03	$	12,731
Unvested at December 31, 2021		1,313,796		$	5.48		8.14	$	33,181