We account for stock-based compensation under the fair value recognition provisions of ASC Topic 718 - Compensation - Stock Compensation. We recognize stock-based compensation cost over the award’s requisite service period on a straight-line basis for time-based restricted stock grants and performance-based restricted stock grants. We record forfeitures as they occur for all stock-based compensation.


	Three Months Ended March 31,
		2024		2023
Employee stock-based compensation expense
Pre-tax		$	369	$	309
Post-tax (1)		292		244
Director stock-based compensation expense
Pre-tax		59		26
Post-tax (1)		47		21

We had approximately $1,886,000 of unrecognized stock compensation expense at March 31, 2024 related to non-vested stock-based compensation granted, which we expect to recognize over a weighted-average period of approximately 1.7 years. We had approximately $41,000 of unrecognized director stock-based compensation expense at March 31, 2024 related to non-vested director stock-based compensation granted, which we expect to recognize over a weighted-average period of approximately 0.2 years.

Stock-based compensation cost for restricted stock awards, restricted stock units and performance stock units is measured based on the closing fair market value of our common stock on the date of grant, which vest in equal installments over the requisite service period of typically three years. Restricted stock awards granted to non-employee directors vest over a one-year period. Each restricted stock unit and performance stock unit represents our obligation to deliver to the holder one share of common stock upon vesting.

Performance stock units vest based on the Company's return on average equity compared to a defined group of peer companies. On the grant date, we issue the target number of performance stock units. They are subject to forfeitures if performance goals are not met. The actual number of performance stock units earned can vary from zero to 150 percent of the target for the 2022 and 2021 awards.

We granted 30,000 shares of restricted common stock during the three months ended March 31, 2024, which had a weighted-average grant date fair value of $9.46. We did not grant shares of restricted common stock during the three months ended March 31, 2023.

The following table presents certain information related to the activity of our non-vested restricted common stock grants:


	Number of Restricted Shares	Weighted Average Grant Date Fair Value
Outstanding as of December 31, 2023(1)	445,646	$	2.64
Granted	30,000	9.46
Less: Forfeited	856	3.59
Less: Vested	32,233	4.36
Outstanding as of March 31, 2024	442,557	$	2.98

Stock option fair value was estimated on the grant date using the Black-Scholes-Merton formula. Stock options vest in equal installments over the requisite service period of typically three years. The following weighted-average assumptions were used to value the stock options granted:


	2024		2023
Expected annual dividend yield	—	%	—	%
Expected volatility	—	%	80.84	%
Risk-free interest rate	—	%	3.44	%
Expected term	N/A		6 years

The expected annual dividend yield for our options granted during 2024 and 2023 is based on no dividends being paid in future quarters. The expected volatility is a historical volatility calculated based on the daily closing prices over a period equal to the expected term. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the grant date. Expected term takes into account the three-year graded vesting term and the 10-year contractual term of the option.

The following table presents certain information related to the activity of our non-vested stock option grants:


	Number of Stock Options	Weighted Average Exercise Prices		Weighted Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (3)
Outstanding as of December 31, 2023(1)	1,028,760	$	3.83	7.80	$	6,151,000
Granted	—	—		—	—
Less: Forfeited	—	—		—	—
Less: Expired	—	—		—	—
Less: Exercised	—	—		—	—
Outstanding as of March 31, 2024	1,028,760	$	3.83	7.55	$	7,368,000

Vested as of March 31, 2024(2)	920,818	$	4.78	7.31	$	3,736,000
Exercisable as of March 31, 2024	580,568	$	4.78	7.31	$	3,736,000

(2) The vested shares are calculated based on all vested shares at March 31, 2024, inclusive of those that have since expired. The weighted average exercise prices, weighted-average remaining contractual term and aggregate intrinsic value is calculated based on only vested shares that are outstanding and exercisable at March 31, 2024.