Stock-Based Compensation Expense

9 Months Ended

Sep. 30, 2025

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation Expense

12.   Stock-Based Compensation Expense. Stock-based compensation expense before income tax expense for the three and nine-month periods ended September 30, 2025 and 2024 consisted of the following (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2025		2024		2025		2024
Cost of sales
Nonqualified stock options	$	126	$	150	$	777	$	875
Restricted stock units		351		—		973		—
Total cost of sales		477		150		1,750		875
Research and development
Nonqualified stock options		328		440		965		1,221
Restricted stock units		386		—		1,103		—
Total research and development		714		440		2,068		1,221
Selling, general and administrative
Nonqualified stock options		1,058		1,442		3,637		4,689
Performance-based restricted stock units		8,030		2,884		16,588		7,648
Restricted stock units		2,270		1,074		6,259		2,792
Cash-settled performance-based awards		998		723		3,094		1,733
Cash-settled restricted stock units		65		—		167		—
Total selling, general and administrative		12,421		6,123		29,745		16,862
Stock-based compensation expense before taxes	$	13,612	$	6,713	$	33,563	$	18,958

We recognize stock-based compensation expense (net of a forfeiture rate), for those awards which are expected to vest, on a straight-line basis over the requisite service period. We estimate the forfeiture rate based on our historical experience and expectations about future forfeitures.

Nonqualified Stock Options

During the nine months ended September 30, 2025 and 2024, we did not grant any stock options. As of September 30, 2025, the total remaining unrecognized compensation cost related to non-vested stock options was $5.5 million, which was expected to be recognized over a weighted average period of 1.4 years.

Stock-Settled Performance-Based Restricted Stock Units (“Performance Stock Units”)

During the nine-month periods ended September 30, 2025 and 2024, we granted Performance Stock Units which represented awards of up to 290,120 and 364,810 shares of Common Stock, respectively. Settlement of the Performance Stock Units into shares of Common Stock occurs at the end of the relevant performance periods. The actual number of shares of Common Stock issuable at the end of the performance periods is based upon Company performance towards specified financial performance targets and relative total shareholder return as compared to the Russell 2000 Index (“rTSR”), all as more specifically set forth in the Performance Stock Unit award agreements.

We use Monte-Carlo simulations to estimate the grant-date fair value of the Performance Stock Units linked to total shareholder return. The fair value of each performance stock unit was estimated as of the grant date using the following assumptions for awards granted in the periods indicated below:

	Nine Months Ended
	September 30,
	2025	2024
Risk-free interest rate	4.0%	4.4%
Performance period	2.8 years	2.8 years
Expected dividend yield	—	—
Expected price volatility	28.0%	31.1%

The risk-free interest rate of return was determined using the U.S. Treasury rate at the time of grant with a term equal to the expected term of the award. The expected volatility was based on the weighted average volatility of our stock price and the average volatility of our compensation peer group's stock price. The expected dividend yield was assumed to be zero because, at the time of the grant, we had no plans to declare a dividend.

Compensation expense is recognized using the grant-date fair value for the number of shares that are likely to be awarded based on the performance metrics. Each reporting period, this probability assessment is updated, and cumulative adjustments are recorded based on the financial performance metrics expected to be achieved. At the end of the performance period, cumulative expense is calculated based on the actual performance metrics achieved. As of September 30, 2025, the total remaining unrecognized compensation cost related to stock-settled Performance Stock Units was $28.5 million, which is expected to be recognized over a weighted average period of 1.3 years.

Cash-Settled Performance-Based Awards

During the nine-month periods ended September 30, 2025 and 2024, we granted Performance Stock Units to our Chief Executive Officer that provide for settlement in cash upon achievement of specific metrics (“Liability Awards”), with total target cash incentives in the amount of $1.7 million and $1.6 million, respectively. The Liability Awards entitle him to a target cash payment based upon our level of rTSR performance and achievement of other performance metrics, as defined in the award agreements.

During the nine-month periods ended September 30, 2025 and 2024, we granted additional Performance Stock Units to certain employees that provide for settlement in cash upon our achievement of specified financial metrics. The cash payable upon vesting at the end of the service period is based upon performance against specified financial performance targets and relative total shareholder return as compared to the rTSR, as defined in the award agreements. Compensation expense is recognized in an amount equal to the cash payment likely to be awarded based on the performance metrics.

The potential maximum payout of these Liability Awards is 250% of the target cash incentive, resulting in a total potential maximum payout of $4.7 million and $4.4 million for Liability Awards granted during the nine-month periods ended September 30, 2025 and 2024, respectively. The settlement generally occurs at the end of three-year performance periods based upon the same performance metrics and vesting period as our Performance Stock Units.

The fair value of these Liability Awards is measured at each reporting period until the awards are settled. As of September 30, 2025 and December 31, 2024, the recorded balance associated with these Liability Awards was $5.7 million and $5.1 million, respectively, which have been classified as liabilities and reported in accrued expenses and other long-term obligations within our consolidated balance sheets. As of September 30, 2025, the total remaining unrecognized compensation cost related to Liability Awards was $4.4 million, which was expected to be recognized over a weighted average period of 1.8 years.

Restricted Stock Units

During the nine-month periods ended September 30, 2025 and 2024, we granted restricted stock units to certain employees and non-employee directors representing 135,778 and 158,719 shares of Common Stock, respectively. The expense recognized for restricted stock units is equal to the closing stock price on the date of grant, which is recognized over the vesting period. Restricted stock units granted to each employee are subject to such employee’s continued employment through the vesting date, which is between three to four years from the date of grant. Restricted stock units granted to each non-employee director are subject to such director’s continued service through the vesting date, which is one year from the grant date. As of September 30, 2025, the total remaining unrecognized compensation cost related to restricted stock units was $27.7 million, which was expected to be recognized over a weighted average period of 2.6 years.