STOCK-BASED AWARDS (Tables)

3 Months Ended

Mar. 31, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Stock Option Activity

A summary of stock option activity for the three months ended March 31, 2023 was as follows:

	Outstanding Options
	Number of Options	Weighted Average Exercise Price		Weighted-Average Remaining Contractual Term	Intrinsic Value (in thousands)
Balance as of December 31, 2022	39,011,116	$	1.19	6.52	$	224,721
Options exercised	(2,200,365)	1.00
Options canceled	(360,455)	2.90
Balance as of March 31, 2023	36,450,296	$	1.19	6.27	$	253,828
Options vested and exercisable as of March 31, 2023	29,237,493	$	1.03	5.96	$	206,986

Schedule of Nonvested Restricted Stock Units Activity

A summary of RSUs activity for the three months ended March 31, 2023 was as follows:

	Restricted Stock Units
	Time-Based Shares	Performance-Based Shares	Total Shares	Weighted-Average Grant-Date Fair Value
Balance as of December 31, 2022	38,570,298	2,090,140	40,660,438	$	19.38
Granted	9,280,865	—	9,280,865	8.42
Vested	(2,601,943)	—	(2,601,943)	22.09
Cancelled/Forfeited	(1,184,767)	—	(1,184,767)	18.64
Balance as of March 31, 2023	44,064,453	2,090,140	46,154,593	$	17.04

Schedule of Share-based Compensation Arrangement Awards

The fair value of these performance-based RSUs was measured on the grant date, March 27, 2021, using a Monte Carlo simulation model, with the following assumptions:

Weighted average volatility	60.0	%
Expected term (in years)	5.0
Risk-free interest rate	0.9	%
Expected dividends	—

Summary of Stock-Based Compensation Expense

Total employee and nonemployee stock-based compensation expense for the three months ended March 31, 2023 and 2022, was classified in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands):

	Three Months Ended March 31,
	2023		2022
Cost of revenue	$	574	$	8,599
Research and development	27,983		49,756
Selling, general and administrative	26,705		116,196
Restructuring charges	(1,443)		—
Total	$	53,819	$	174,551