Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2024

Stock-Based Compensation

Schedule of Stock-based Compensation Expense

The following table sets forth the Company’s stock-based compensation expense for the periods indicated (in thousands):

	Year Ended December 31,
	2024		2023
Cost of production	$	60	$	59
General and administrative		12,747		15,204
Other operating expenses		1,926		1,824
Total stock-based compensation	$	14,733	$	17,087

Schedule Stock Option Award Activity

Stock option award activity. Stock option activity under the Company’s stock incentive plans and changes during the year ended December 31, 2024, were as follows:

				Weighted-
				Average
		Weighted-		Remaining		Weighted-
		Average		Contractual		Average		Aggregate
	Number of	Exercise		Term		Grant-Date		Intrinsic
	Options	Price (1)		(years)		Fair Value		Value
Options outstanding at December 31, 2023	8,109,060	$	3.51		8.8
Granted	6,603,419	$	0.71
Forfeited and expired	(609,021)	$	2.57
Exercised	—	$	—
Options outstanding at December 31, 2024	14,103,458	$	2.24		8.4	$	1.90	$	—
Options vested and expected to vest at December 31, 2024	14,103,458	$	2.24		8.4	$	1.90	$	—

(1) Exercise price of options outstanding range from $0.67 to $876 as of December 31, 2024. The higher end of the range is due to the impact of several reverse stock splits during the years 2015 to 2018.

Schedule of Stock Option Pricing Assumptions

The following table sets forth the weighted average Black-Scholes option pricing model assumptions (no dividends were expected) and resulting grant date fair value for the stock options granted during the years ended December 31, 2024, and 2023:

	Year Ended December 31,
	2024			2023
Risk-free interest rate		3.24	%		4.30	%
Expected volatility factor		133	%		153	%
Expected option life (years)		6.0			6.0
Weighted-average fair value	$	0.63		$	1.41

Schedule of Non-vested Restricted Stock Awards

Non-vested restricted stock awards at December 31, 2024, and changes during the year ended December 31, 2024, were as follows:

		Weighted-
		Average
	Number of	Grant-Date
	Shares	Fair Value
Outstanding at December 31, 2023	6,159,341	$	2.30
Granted	5,739,174	$	0.75
Vested and issued	(3,758,389)	$	2.59
Forfeited and expired	(551,982)	$	1.16
Non-vested at December 31, 2024	7,588,144	$	1.08