In July 2018, the Company’s board of directors approved the adoption of a stock plan (the “Stock Plan”) and the board of directors periodically approves changes in the number of authorized shares under the plan. The Stock Plan provides for the grant of restricted stock awards, incentive and non-statutory stock options and restricted stock units (“RSUs”) to employees, nonemployee directors and consultants of the Company. As of March 31, 2026 and December 31, 2025, only stock options had been granted under the Stock Plan. The stock option awards generally include service condition vesting terms of four years, with 25% of the award vesting one year from the vesting commencement date and then ratably over the following 36 months, though some vest over shorter periods, vesting monthly from grant date. Options granted under the Stock Plan generally expire ten years from the date of grant. Options are exercisable only to the extent vested unless early exercise is approved by the Company’s board of directors.

As of March 31, 2026 and December 31, 2025, 31,567 and 35,629 shares of common stock granted pursuant to the early exercise of options were outstanding and subject to the Company’s repurchase right. The exercise price of all stock options granted under the Stock Plan must be at least equal to 100% of the fair value of the Company’s common stock at the date of grant, as determined by the Company's board of directors. As of March 31, 2026, total shares available for grant under the Stock Plan were 359,490.

For the three months ended March 31, 2026 and 2025, the Company recorded stock-based compensation expense as follows (in thousands):


	Three Months Ended March 31,
	2026		2025
Cost of product revenue	$	14	$	8
Cost of service and other revenue		22		13
Research and development		392		229
Selling, general and administrative		1,039		369
Total stock-based compensation expense	$	1,467	$	619

As of March 31, 2026, there was $18.0 million of unamortized stock-based compensation expense which is expected to be recognized over a weighted-average period of 3.3 years.

Stock option activity for the three months ended March 31, 2026 was as follows:



								Aggregate
				Exercise		Remaining		intrinsic
	Options			price per		contractual		value
	outstanding			share		life (in years)		(in thousands)
Balance outstanding, December 31, 2025		5,842,551		$	3.18		8.27	$	25,767
Options granted		1,433,765		$	7.59
Options exercised		(824,237	)	$	2.85
Options cancelled/forfeited/expired		(14,832	)	$	3.78
Balance outstanding, March 31, 2026		6,437,247		$	4.21		8.37	$	56,256
Vested and expected to vest at March 31, 2026		6,785,106		$	4.16		8.39	$	59,223
Exercisable at March 31, 2026		3,318,094		$	2.97		7.60	$	29,512

The weighted-average grant date fair value of options granted was $4.89 and $2.44 per share for the three months ended March 31, 2026 and 2025, respectively. The intrinsic value of options exercised during the three months ended March 31, 2026 and 2025 was $4.5 million and $0.7 million, respectively.

The Company estimated the fair value of stock options granted during the three months ended March 31, 2026 and 2025, using the Black-Scholes option pricing model with the following weighted-average assumptions:


	Three Months Ended March 31,
	2026			2025
Expected dividend yield		0.0	%		0.0	%
Risk-free interest rate		3.87	%		4.45	%
Expected volatility		68.3	%		83.1	%
Expected term (in years)		6.0			6.0

Stock activity during the three months ended March 31, 2026 for grants of restricted stock awards (“RSAs”) to employees outside of the Stock Plan was as follows:


				Weighted-
	RSAs			average
	outstanding			grant date FV
Balance outstanding, December 31, 2025		34,877		$	4.18
RSAs vested		(5,583	)
Balance outstanding, March 31, 2026		29,294		$	4.18

For the three months ended March 31, 2026 and 2025, the total fair value of shares vested was de minimis.

In April 2025, the Company adopted the Employee Phantom Option Plan, which allows for the issuance of Phantom Options to purchase Phantom Shares of the Class B Common Stock of the Company. Following the IPO, Phantom Shares may be converted into common shares at a defined conversion price. Upon completion of the IPO and government registration, all outstanding Phantom Options automatically convert into options to acquire common stock. The Company issued 8,945 phantom stock options during the three months ended March 31, 2026 with a weighted-average exercise price of $7.59 per share.