Stock-based compensation expense for each employee and director is presented in the same statement of operations caption as their cash compensation. Stock-based compensation expense by statement of operations caption and the related income tax benefit were as follows:


	Three Months Ended March 31,
(In thousands)	2025		2024
Cost of sales	$	16	$	27
Research and development expenses	158		231
Selling, general and administrative expenses:
Employees	1,276		1,551
Outside directors	334		95
Total employee and director stock-based compensation expense	$	1,784	$	1,904
Income tax benefit	$	247	$	287

Non-vested restricted stock award activity was as follows:


	Shares (in thousands)	Weighted-Average Grant Date Fair Value
Non-vested at December 31, 2024	595	$	13.07
Granted	—	—
Vested	(106)	20.91
Forfeited	(1)	10.68
Non-vested at March 31, 2025	488	$	11.38

As of March 31, 2025, we expect to recognize $3.7 million of total unrecognized pre-tax stock-based compensation expense related to non-vested restricted stock awards over a weighted-average life of 1.5 years.


	Shares (in thousands)	Weighted-Average Grant Date Fair Value
Non-vested at December 31, 2024	116	$	4.72
Granted	—	—
Vested	—	—
Forfeited	—	—
Non-vested at March 31, 2025	116	$	4.72

The assumptions we utilized in the Monte Carlo simulation model and the resulting weighted average fair value of performance stock grants were the following:


	Three Months Ended March 31,
	2025			2024
Weighted average fair value of grants	$	—		$	4.72
Risk-free interest rate	—		%	4.08		%
Expected volatility	—		%	57.00		%
Expected life in years	0.00			2.73

As of March 31, 2025, we expect to recognize $0.3 million of total unrecognized pre-tax stock-based compensation expense related to non-vested performance stock awards over a weighted-average period of 1.6 years.

In April 2025, certain executives were granted 284,316 performance stock awards, in the aggregate, in connection with the 2024 annual review cycle. These awards vest only upon the satisfaction of a three-year service condition and market conditions based upon the price per share of our common stock. The fair value of these awards is $0.6 million, as determined by a Monte Carlo simulation model as of the grant date, and is expected to be recognized over a weighted-average period of 2.7 years.


	Number of Options (in thousands)	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2024	779	$	35.67
Granted	—	—
Exercised	—	—			$	—
Forfeited/canceled/expired	(88)	44.95
Outstanding at March 31, 2025 (1)	691	$	34.50	3.25	$	—
Vested and expected to vest at March 31, 2025 (1)	691	$	34.50	3.25	$	—
Exercisable at March 31, 2025 (1)	612	$	35.73	3.02	$	—

(1)The aggregate intrinsic value represents the total pre-tax value (the difference between our closing stock price on the last trading day of the first quarter of 2025 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had they all exercised their options on March 31, 2025. This amount will change based on the fair market value of our stock.

As of March 31, 2025, we expect to recognize $0.6 million of total unrecognized pre-tax stock-based compensation expense related to non-vested stock options over a remaining weighted-average life of 0.4 years.