Stock-Based Compensation Plans

12 Months Ended

Dec. 31, 2025

Stock-Based Compensation Plans [Abstract]

14. Stock-Based Compensation Plans

In 2009, the Company adopted its 2009 Equity Incentive Plan which provided for the grant of stock options to the Company’s employees, members of the Board of Directors and consultants. Effective upon the Company’s IPO in August 2025, the Company’s Board of Directors approved the termination of the 2009 Equity Incentive Plan and the adoption of the 2025 Performance Incentive Plan (“2025 Plan”). Options granted under the 2025 Plan may be either incentive stock options (“ISOs”) or nonqualified stock options (“NSOs”). ISOs may be granted only to employees. NSOs, Stock Appreciation Rights, Restricted Stock, and Restricted Stock Units (“RSUs”) may be granted to employees, members of the Board of Directors and consultants. A total of 17,346,193 shares of common stock were initially reserved for issuance pursuant to the 2025 Plan. In addition, the shares reserved for issuance under the 2025 Plan will also include shares reserved but not issued under the 2009 Equity Incentive Plan, plus any share awards granted under the 2009 Equity Incentive Plan that expire or terminate without having been exercised in full or that are forfeited or repurchased. In addition, the number of shares available for issuance under the 2025 Plan will also include an annual increase on the first day of each fiscal year beginning in fiscal 2026, equal to or greater than (i) 5% of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year less any Board of Directors-approved increase(s) during the preceding fiscal year; or (ii) an amount as determined by the Board of Directors.

Options under the 2009 Equity Incentive Plan and 2025 Plan have a term of ten years from the grant date. The option exercise price will be determined by the Board of Directors, but will be no less than 100% of the fair market value per share on the date of grant. In addition, in the case of an ISO granted to an employee who owns stock

representing more than 10% of the voting power of all classes of stock of the Company, the per share exercise price will be no less than 110% of the fair market value per share on the date of grant. Through December 31, 2025 and 2024, options granted generally vest over (i) four years with 25% vesting on the first anniversary of the issuance date and 1/48th per month thereafter or (ii) vesting monthly in equal installments over four years.

Stock option activity under the Company’s 2009 Equity Incentive Plan and 2025 Plan is set forth below (in thousands, except share and per share amounts):


	Number of Options	Awards Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Balance at December 31, 2024	8,537,210	$	4.72	7.96	$	68,256
Options granted	2,552,686	$	18.51
Options exercised	(617,134)	$	5.33
Options forfeited	(469,508)	$	7.97
Balance at December 31, 2025	10,003,254	$	8.05	7.83	$	211,109
Vested and exercisable, December 31, 2025	4,371,128	$	5.33	6.72	$	104,102
Vested and expected to vest, December 31, 2025	10,003,254	$	8.05	7.83	$	211,109

The weighted-average grant date fair value of options granted during the years ended December 31, 2025, 2024 and 2023 was $10.54, $3.59 and $1.26 per share, respectively. The total grant date fair value of options vested was $8.6 million, $2.0 million and $3.2 million during the years ended December 31, 2025, 2024 and 2023, respectively.

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock options and the fair value of the Company’s common stock for stock options that were in-the-money at each reporting period. The aggregate intrinsic value of stock options exercised for the years ended December 31, 2025, 2024 and 2023 was $10.1 million. $1.7 million and $4,000, respectively.

Restricted Stock Units

In August 2025, the Company began granting RSUs under the 2025 Plan. RSUs generally vest over four years in equal quarterly increments. The fair value of RSUs is based on the Company’s closing stock price on the date of grant. A summary of RSUs activity is set forth below:


	Number of Restricted Stock Units		Awards Weighted-Average Grant Date Fair Value
Unvested balance at December 31, 2024		—	$	—
Awards granted		987,025	$	20.22
Awards vested		(47,018)	$	19.00
Awards canceled		(32,304)	$	19.00
Unvested balance at December 31, 2025		907,703	$	20.33

2025 Employee Stock Purchase Plan

Effective upon the Company’s IPO, in August 2025, the Company’s Board of Directors adopted the 2025 Employee Stock Purchase Plan (“2025 ESPP”), under which eligible employees are permitted to purchase common stock at a discount through payroll deductions. A total of 1,233,964 shares of common stock are reserved for issuance and will be increased on the first day of each fiscal year, beginning in 2026, by an amount equal to the lesser of (i) 1.0% of the issued and outstanding shares of common stock as of the last day of the immediately preceding fiscal year; or (ii) an amount as determined by the Board of Directors. The price of the common stock purchased will be the lower of 85% of the fair market value of the common stock at the beginning of an offering period or at the end of a purchase period. The 2025 ESPP is intended to qualify as an “employee stock purchase plan” within the meaning of Section 423 of the Internal Revenue Code of 1986, as amended (the “IRC”).

Stock-Based Compensation

The Company estimated the fair value of stock options using the Black-Scholes option-pricing model based on the following assumptions:


	Year Ended December 31,
	2025		2024		2023
Expected life (in years)		6.00		6.00		6.00
Expected volatility		55.0%-57.9%		53.7%-55.0%		54.7%-55.7%
Risk-free interest rate		3.7%-4.2%		3.5%-4.5%		4.2%
Dividend yield		—%		—%		—%

The Company estimated the fair value of the shares to be issued under the Company’s 2025 ESPP using the Black-Scholes option-pricing model based on the following assumptions:


		Year Ended December 31, 2025
Expected life (in years)		0.6
Expected volatility		58.1%
Risk-free interest rate		4.1%
Dividend yield		—%

The significant assumptions used in these calculations are summarized as follows:

Fair value of common stock. Because there had been no public market for the Company’s common stock prior to the IPO, the fair value of common stock shares underlying stock options has historically been determined by the Board of Directors at the time of option grant by considering an independent valuation performed by a third-party valuation firm as well as a number of objective and subjective factors, including a valuation of comparable companies, sales of convertible preferred stock to unrelated third parties, operating and financial performance, the lack of liquidity of capital stock and general and industry specific economic outlook, among other factors. The fair value of common stock was determined in accordance with applicable elements of the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. Subsequent to its IPO, the fair value of the underlying common stock is based on the closing price of the Company’s common stock on the Nasdaq Stock Market on the date of grant.

Expected term. The expected term of stock options represents the weighted-average period the stock options are expected to remain outstanding. The Company does not have sufficient historical exercise and post-vesting termination activity to provide accurate data for estimating the expected term of options and has opted to use the “simplified method,” whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option.

Expected volatility. As the Company was not publicly traded prior to the IPO and does not have sufficient trading history after the IPO, the expected volatility for the Company’s stock options was determined by using an average of historical volatilities of selected industry peers deemed to be comparable to the Company’s business corresponding to the expected term of the awards.

Risk-free interest rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities corresponding to the expected term of the awards.

Expected dividend yield. The expected dividend rate is zero as the Company currently has no history or expectation of declaring dividends on its common stock.

The Company also issues stock options with vesting based upon completion of performance goals. The fair value for these performance-based awards is recognized over the period during which the goals are to be achieved. Stock-based compensation expense recognized at fair value includes the impact of estimated probability that the goals would be achieved, which is assessed prior to the requisite service period for the specific goals.

Total stock-based compensation expense is as follows (in thousands):


	Year Ended December 31,
	2025		2024		2023
Cost of revenue	$	413	$	307	$	440
Research and development⁽¹⁾		3,434		2,151		3,339
Selling, general and administrative		10,118		7,755		8,722
Total stock-based compensation	$	13,965	$	10,213	$	12,501

(1)Includes stock-based compensation expense of $627,000 during the year ended December 31, 2023 related to a repurchase of common shares from one employee, as described below.

As of December 31, 2025, total unrecognized stock-based compensation costs related to unvested stock options was $30.5 million, which is expected to be recognized over a remaining weighted-average period of 3.17 years, a total of $17.7 million of unrecognized compensation costs related to unvested RSUs is expected to be recognized over a period of approximately 3.72 years, and $762,000 of unrecognized compensation costs related to the ESPP is expected to be recognized over 0.18 years.

In January 2023, the fair value of the Company’s common stock declined from $41.67 to $2.22 per share, prompting the Company to reduce the exercise price of certain stock options to $2.22, effective July 10, 2023. No other changes to the stock options’ terms were made. The Company calculated the incremental fair value by calculating the fair value of the award immediately before and immediately after the modification. The fair value of the award immediately before the repricing is based on assumptions (including volatility, expected term and risk free interest rate) that reflect the facts and circumstances on the modification date and therefore, differ from the fair value calculated on the grant date. The average additional compensation per award from the modification was $0.09 and the aggregate incremental expense was $649,000, of which $340,000 was immediately recognized on the modification date and the remaining amount is recognized over the options’ remaining requisite service period.

In March 2023, the Board of Directors approved a repurchase of 102,739 common shares from an employee of the Company at a purchase price of $8.32 per share for total consideration of $855,000. The fair value of the repurchased common shares was $228,000, and the difference between the repurchase price and fair value of the common shares of $627,000 was recorded as stock-based compensation expense within research and development expense in the consolidated statements of operations and comprehensive loss during the year ended December 31, 2023.