Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Weighted Average Valuation Assumptions Used for Options

Following are the weighted average valuation assumptions used for options:

	Year Ended December 31,
	2021			2020			2019
Valuation assumptions
Expected dividend yield		—	%		—	%		—	%
Expected volatility		59	%		60	%		57	%
Expected term (years)		4.66			4.49			6.05
Risk-free interest rate		0.71	%		1.46	%		2.33	%

Summary of Classification of Stock Based Compensation Expense

The following table presents classification of stock-based compensation expense within the consolidated statements of operations:

	Year Ended December 31,
	2021		2020		2019
Cost of sales	$	3,858	$	1,384	$	376
Research and development		7,440		3,050		460
Sales and marketing		1,281		516		311
General and administrative		13,911		5,595		1,046
Total stock-based compensation	$	26,490	$	10,545	$	2,193

Summary of Stock Option Activity

Stock option activity was as follows:

	Number of shares			Weighted average exercise price		Weighted average remaining contractual term (years)		Aggregate intrinsic value
Beginning, January 1, 2021		7,257,460		$	12.14
Granted		1,696,327		93.13
Exercised		(1,120,981	)		7.00
Forfeited		(149,346	)		41.47
Expired		(3,119	)		1.70
Balance, December 31, 2021		7,680,341			30.19		7.67	$	35,584
Exercisable, December 31, 2021		3,473,716			10.83		6.75	$	83,306