
	Three months ended September 30,				Nine months ended September 30,
	2026		2025		2026		2025
Cost of services	$	371	$	219	$	1,312	$	580
Research and development	1,549		1,749		4,342		3,590
Selling, general and administrative	6,333		8,618		17,937		18,212
Total stock-based compensation expense(1)(2)	$	8,253	$	10,586	$	23,591	$	22,382

(1)The Company recorded an aggregate reversal of stock-based compensation of $0.5 million and $0.6 million during the three months ended September 30, 2026 and 2025, respectively, and $3.7 million and $1.4 million during the nine months ended September 30, 2026 and 2025, respectively, due to forfeiture activities upon employee terminations.

(2)Includes $0.4 million and $0.4 million of expenses related to the 2021 Employee Stock Purchase Plan for the three months ended September 30, 2026 and 2025, respectively, and $2.6 million and $1.1 million of expenses for the nine months ended September 30, 2026 and 2025, respectively.

The Company maintains the Amended and Restated 2021 Equity Incentive Plan (as amended and restated, the “2021 Plan”) and the 2023 Equity Inducement Plan (the “Equity Inducement Plan”), which allow for grants of equity awards. As of September 30, 2026, there was an aggregate of 3,916,942 shares available for grants of equity awards under the 2021 Plan and Equity Inducement Plan.

All stock options granted under the 2021 Plan are accounted for as service-based equity awards. The following summarizes the stock option activity during the nine months ended September 30, 2026:


	Stock Options	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (years)	Aggregate Intrinsic Value
Outstanding at December 31, 2025	199,454	$	65.29	6.41	$	14,015

Exercised	(2,314)	$	25.27
Forfeited and canceled	(14,747)	$	124.71
Outstanding at September 30, 2026	182,393	$	61.19	5.74	$	2,667
Options exercisable at September 30, 2026	182,393	$	61.19	5.74	$	2,667

There were no unvested options outstanding as of September 30, 2026. Accordingly, as of September 30, 2026, unrecognized stock-based compensation cost related to the unvested portion of the Company’s stock options was zero.

The weighted-average grant-date fair value and total fair value of options with tranches vested during the nine months ended September 30, 2026 were $45.37 and $0.9 million, respectively.

There were no options granted during the nine months ended September 30, 2026. The aggregate intrinsic value of options exercised during the nine months ended September 30, 2026 was $0.1 million, and is calculated based on the difference between the exercise price and the fair value of the Company’s Class A common stock as of the exercise date.

Restricted stock units granted under the 2021 Plan are accounted for as either service-based restricted stock units (“RSUs”) or performance-based restricted stock units (“PRSUs”). Restricted stock units convert to Class A common stock on a one-for-one basis as the awards vest. The Company measures the value of restricted stock units at fair value based on the closing price of the underlying common stock on the grant date. The following table summarizes restricted stock unit activity during the nine months ended September 30, 2026:


	Restricted Stock Units	Weighted-Average Grant Date-Fair Value Per Unit
Outstanding at December 31, 2025	1,519,733	$	42.91
Granted(1)	729,146	$	76.95
Vested	(579,592)	$	38.74
Forfeited	(199,062)	$	73.78
Outstanding at September 30, 2026	1,470,225	$	57.38

During the nine months ended September 30, 2026, the Company approved awards of 87,966 PRSUs to certain executives. The grant date fair value of the PRSUs is based on the fair value of the Company’s Class A common stock on the grant date. The awards have both service-based and performance-based vesting conditions. The actual number of shares earned on vesting ranges from 0% to 200% of the target number of shares granted, depending on the attainment of specified performance goals established for the years ending December 31, 2026 and 2027. In addition, previously awarded PRSUs granted during the nine months ended September 30, 2025 achieved the maximum 200% performance level, resulting in the issuance of 36,839 incremental shares during the nine months ended September 30, 2026.

The total fair value of restricted stock units vested during the nine months ended September 30, 2026 was $22.5 million. As of September 30, 2026, unrecognized stock-based compensation expense related to the Company’s restricted stock units was $44.5 million, which is expected to be recognized on a graded-vesting basis over a weighted-average period of 2.0 years.

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. 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 Company issued 39,918 shares of Class A common stock under the 2021 ESPP during the nine months ended September 30, 2026. As of September 30, 2026, a total of 1,051,915 shares of Class A common stock have been reserved for future issuance under the 2021 ESPP.