Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Schedule of Share-based Payment Arrangement, Option, Activity

A summary of the status of the 2015 Plan and 2021 Plan as of December 31, 2023 and March 31, 2024, and changes during the three month period ended March 31, 2024, is presented below:

	Options Outstanding
	Number of Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2023	13,249,983	$	3.60	6.50	$	927
Granted	—	—
Exercised	(25,000)	1.27
Forfeited	(62,389)	4.38
Cancelled	(228,719)	3.85
Outstanding at March 31, 2024	12,933,875	3.60		6.17	499
Vested and exercisable at March 31, 2024	8,668,272	4.10		4.99	499

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The following weighted average assumptions were used for issuances during the three months ended March 31, 2023, for employees and non-employees:

	Three Months Ended March 31,
	2023
Risk-free interest rate	4.12	%
Dividend yield	—
Volatility	45.09	%
Expected lives (in years)	4.60

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions

The following table summarizes the weighted-average assumptions used in estimating the fair value of the 2021 ESPP grants for the following offering periods presented, using the Black Scholes option-pricing model:

	Offering Period - November 3, 2023 to May 2, 2024		Offering Period - May 3, 2023 to November 2, 2023		Offering Period - November 3, 2022 to May 2, 2023
Risk-free interest rate	5.45	%	5.08	%	4.44	%
Dividend yield	—		—		—
Volatility	43.12	%	45.59	%	43.42	%
Expected lives (years)	0.5		0.5		0.5

Schedule of Share-based Payment Arrangement, Restricted Stock Unit, Activity

RSU activity during the three months ended March 31, 2024 was as follows:

	Number of Shares	Weighted-Average Grant Date Fair Value per Share
Unvested at December 31, 2023	10,264,090	$	1.93
Granted	1,513,365	0.86
Vested	(619,392)	2.68
Forfeited	(611,461)	2.23
Unvested at March 31, 2024	10,546,602	$	1.71

Schedule of Share-Based Payment Arrangement, Performance Shares, Activity

PSU activity during the three months ended March 31, 2024 was as follows:

	Target Number of Shares	Weighted-Average Grant Date Fair Value per Share
Unvested at December 31, 2023	525,108	$	5.29
Granted	654,857	0.13
Vested	—	—
Forfeited	—	$	—
Unvested at March 31, 2024	1,179,965	$	2.35

Schedule of Stock-based Compensation Expense

Stock-based compensation expense, recognized as selling, general, and administrative expense in the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2024 and 2023, was comprised of the following:

	Three Months Ended March 31,
(in thousands)	2024		2023
Stock-based compensation, net of amounts capitalized	$	3,344	$	5,670
Capitalized stock-based compensation	87		242
Total stock-based compensation	$	3,431	$	5,912