Stock-Based Compensation

12 Months Ended

Dec. 31, 2024

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation Expense

Stock-based compensation expense is included within the consolidated statements of operations and comprehensive loss as follows:


	Year Ended December 31,
	2024		2023
Cost of services	$	431	$	(1,217)
Research and development	1,192		(2,585)
Selling and marketing	1,089		(1,266)
General and administrative	6,426		4,742
Total stock-based compensation expense1,2	$	9,138	$	(326)

1 The Company recorded an aggregate reversal of stock-based compensation of $3.9 million and $24.7 million during the years ended December 31, 2024 and 2023, respectively, due to forfeiture activities upon employee terminations.

2 Includes $0.6 million of expense related to the 2021 Employee Stock Purchase Plan during year ended December 31, 2024.

Stock Incentive Plans

The Company maintains the Amended and Restated 2021 Equity Incentive Plan (as amended and restated, the “2021 Plan”), which allows for grants of stock-based awards. No awards granted under the 2021 Plan are exercisable after 10 years from the date of grant, and the awards granted under the 2021 Plan generally vest over a four-year period on a graded vesting basis; however, the Company has also granted certain restricted stock units (“RSUs”) with vesting terms beginning 12 months from the grant date and vesting immediately on the grant date. On January 1 of each year through 2031, the aggregate number of shares of Class A common stock reserved for issuance under the 2021 Plan may be increased automatically by the number of shares equal to 5% of the total number of shares of all classes of common stock issued and outstanding immediately preceding December 31. In January 2024, the number of Class A common stock reserved for future issuance under the 2021 Plan automatically increased by 1,298,943 shares.

The Company also maintains the 2023 Equity Inducement Plan (the “Equity Inducement Plan”), which allows for grants of equity awards of the Company’s Class A common stock to individuals who were not previously an employee or director of the Company, or following a bona fide period of non-employment, as an inducement material to such persons entering into employment with the Company.

As of December 31, 2024, there was an aggregate of 1,857,260 shares available for grants of stock options or other awards under the 2021 Plan and Equity Inducement Plan. In January 2025, the number of Class A common stock reserved for future issuance under the 2021 Plan automatically increased by 1,400,827 shares.

Stock Option Activity

All stock options granted under the 2021 Plan are accounted for as time-based equity awards. The following summarizes the stock option activity during the year ended December 31, 2024:


	Stock Options Outstanding	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value
Balance at December 31, 2023	497,976	$	42.80	5.55	$	—
Options granted	—	$	—
Options exercised	(68,453)	$	5.77
Options forfeited and canceled	(88,243)	$	63.45
Balance at December 31, 2024	341,280	$	44.83	5.99	$	12,429
Options exercisable at December 31, 2024	290,963	$	40.47	5.74	$	11,799

Non-vested options outstanding at the end of the year were 50,317 with weighted average grant-date fair value of $14.52. As of December 31, 2024, unrecognized stock-based compensation cost related to the unvested portion of the Company’s stock options was $0.5 million, which is expected to be recognized on a graded-vesting basis over a weighted-average period of 1.0 years.

The weighted-average grant-date fair value and total fair value of options with tranches vested was $34.42 and $0.7 million for the year ended December 31, 2024, respectively, and $25.07 and $1.5 million for the year ended December 31, 2023, respectively.

The aggregate intrinsic value of exercised options was $2.3 million and $0.3 million in the years ended December 31, 2024 and 2023, respectively, and is calculated based on the difference between the exercise price and the fair value of the Company’s common stock as of the exercise date. The weighted-average grant-date fair value of options forfeited and canceled was $7.46 for the year ended December 31, 2024.

There were no options granted during the year ended December 31, 2024. The fair value of the stock option awards granted during the year ended December 31, 2023 were estimated using the Black-Scholes option pricing model with the following assumptions:


			2023
Expected volatility			105.0%
Weighted-average expected volatility			105.0%
Expected term (in years)			5.5
Risk-free interest rate			4.03%
Dividend yield			—
Fair value of Class A common stock			$6.35

Restricted Stock Units (RSU)

The Company issued time-based RSUs to employees under the 2021 Plan. The RSUs automatically convert to common stock on a one-for-one basis as the awards vest. The Company measures the value of RSUs at fair value based on the closing price of the underlying common stock on the grant date. The RSUs granted generally vest over a four-year vesting period from the grant date, however, the Company also granted certain RSUs with vesting term beginning 12 months from the grant date and vesting immediately on the grant date. The following table summarizes the activity related to the Company’s time-based RSUs:


	Restricted Stock Units Outstanding	Weighted Average Grant Date Fair Value Per Unit
Balance at December 31, 2023	1,507,877	$	15.48
Restricted Stock Units granted	1,187,165	$	11.37
Restricted Stock Units vested	(471,663)	$	17.72
Restricted Stock Units forfeited	(353,818)	$	15.63
Balance at December 31, 2024	1,869,561	$	12.03

The total fair value of RSUs vested for the years ended December 31, 2024 and 2023 was $2.1 million and $6.6 million, respectively. As of December 31, 2024, unrecognized stock-based compensation cost related to the Company’s RSUs was $10.7 million, which is expected to be recognized on a graded-vesting basis over a weighted-average period of 1.8 years.

Employee Stock Purchase Plan

The 2021 Employee Stock Purchase Plan (the “2021 ESPP”) authorizes the issuance of shares of Class A common stock pursuant to purchase rights granted to employees. On January 1 of each year through 2031, the aggregate number of shares of Class A common stock reserved for issuance under the 2021 ESPP may be increased automatically by the number of shares equal to 1% of the total number of shares of all classes of common stock issued and outstanding immediately preceding December 31.

The 2021 ESPP became open for enrollment in April 2024. Under the 2021 ESPP, eligible employees may purchase shares of the Company’s Class A common stock at a discount through payroll deductions during each discrete six-month offering period. The purchase price under each discrete offering period is equal to 85% of the lesser of the fair market value of the Class A common stock on the first and last day of the offering period.

The first offering period was completed on October 31, 2024 and the Company issued 26,773 shares under the 2021 ESPP during the year ended December 31, 2024. A total of 569,831 shares of Class A common stock were reserved for future issuance under the 2021 ESPP as of December 31, 2024. In January 2025, the number of Class A common stock reserved for future issuance under the 2021 ESPP automatically increased by 280,165 shares.