The Company recognized total stock-based compensation expense during the three and six months ended June 30, 2025 and 2024 as follows (table in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2025		2024		2025		2024
Service-based Awards:

Restricted Stock Units	$	187	$	159	$	481	$	277
Stock Option Awards	195		179		346		312
Total	$	382	$	338	$	827	$	589

A summary of the Company’s performance-based restricted stock awards during the six months ended June 30, 2025 is as follows:


Performance-based Restricted Stock Awards	Number of Shares	Weighted Average Grant-Date Fair Value
Unvested at January 1, 2025	891	$	62.70

Unvested at June 30, 2025	891	$	62.70

Performance-based restricted stock awards are measured based on their fair value on the date of grant and amortized over the vesting period of 20 months. As of June 30, 2025, there is no unrecognized stock-based compensation expense related to performance-based restricted stock awards.

During the three months ended June 30, 2025, the Company granted 717,000 restricted stock units with a market condition ("RSU-MC") under its Amended and Restated 2018 Long Term Incentive Plan. The RSU-MCs are subject to both service and market based vesting conditions.

The RSU-MCs will vest, subject to the recipient's continued employment through the vesting date, if the average closing price of the Company's common stock equals or exceeds $2.14 per share for any consecutive 60-day trading period occurring prior to the third anniversary of the grant date. Except in the event of a change in control or termination due to death or disability, no portion of the award will vest before the first anniversary of the grant date. The RSU-MCs qualify as equity instruments and are accounted for under ASC 718, Compensation, Stock Compensation ("ASU 718").

The fair value of RSU-MCs was measured on the date of grant using the Monte Carlo Simulation valuation model. The stock-based compensation expense recorded in connection with these restricted stock units during the six months ended June 30, 2025 was insignificant. The vesting periods range from one to three years.

A summary of the Company’s service-based restricted stock units during the six months ended June 30, 2025 is as follows:


Service-based Restricted Stock Units	Number of Shares	Weighted Average Grant-Date Fair Value
Unvested at January 1, 2025	584,309	$	1.72
Granted	1,000,000	1.07
Vested	(417,649)	1.85

Unvested at June 30, 2025	1,166,660	$	1.12

The fair value of service-based restricted stock units is measured on the date of grant and amortized over the vesting period. The vesting periods range from one to three years. As of June 30, 2025, the unrecognized stock-based compensation expense was $1.1 million, which is expected to be recognized over the next 1.6 years.

The fair value of the service-based stock option awards granted during the six months ended June 30, 2025 were based on the following assumptions:


	Six Months Ended June 30, 2025	Six Months Ended June 30, 2024
Exercise price	$1.07	$1.39 - $1.80
Expected stock price volatility	90.4%	81.8%
Risk-free interest rate	4.1%	4.31% - 4.45%
Term (years)	5.86	5.61 - 5.62

A summary of the Company’s service-based stock option activity for the six months ended June 30, 2025 is as follows:


Service-based Stock Option Awards	Shares Underlying Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2025	1,886,247	$	3.98
Granted	1,501,500	1.07

Forfeited	(9,354)	1.59
Expired	(36,501)	1.73
Outstanding at June 30, 2025	3,341,892	$	2.71	8.6	$	—
Exercisable at June 30, 2025	913,461	$	6.41	7.0	$	—

The aggregate intrinsic value is calculated as the difference between the closing price of the Company's common stock at the date indicated and the exercise price of the stock options that had strike prices below the closing price.

As of June 30, 2025, total stock-based compensation expense related to unvested options not yet recognized totaled approximately $1.5 million, which is expected to be recognized over the next 2.8 years.