Stock-Based Compensation

3 Months Ended

Mar. 31, 2023

Equity incentive plans. In February 2011, the Company’s stockholders approved the Gevo, Inc. 2010 Stock Incentive Plan (as amended and restated to date, the "2010 Plan"), and the Employee Stock Purchase Plan (the "ESPP").

The 2010 Plan provides for the grant of non-qualified stock options, incentive stock options, stock appreciation rights, restricted stock awards, restricted stock units and other equity awards to employees and directors of the Company. In June 2021, upon approval of the stockholders at the 2021 Annual Meeting of Stockholders, the 2010 Plan was amended and restated, which increased the number of shares of common stock reserved for issuance under the 2010 Plan to 22,980,074 shares. At March 31, 2023, 4,109,441 shares were available for future issuance under the 2010 Plan.

Stock-based compensation expense. The Company records stock-based compensation expense during the requisite service period for share-based payment awards granted to employees and non-employees.

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


	Three Months Ended March 31,
		2023		2022
Equity Classified Awards
Cost of production		$	18	$	193
General and administrative		3,923		3,494
Other		736		357
Total equity classified awards		4,677		4,044





Liability Classified Awards
General and administrative		—		214

Total liability classified awards		—		214
Total stock-based compensation		$	4,677	$	4,258

Stock option award activity. Stock option activity under the Company’s stock incentive plans and changes during the three months ended March 31, 2023, were as follows:


	Number of Options	Weighted-Average Exercise Price (1)		Weighted-Average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Options outstanding at December 31, 2022	5,945,321	$	4.65	9.6	$	—
Granted	55,918	$	2.12		$	—
Canceled or forfeited	(26,173)	$	8.04		$	—
Exercised	—	$	—		$	—
Options outstanding at March 31, 2023	5,975,066	$	4.62	9.1	$	—
Options vested and expected to vest at March 31, 2023	1,492,796	$	5.26	0.5	$	—

(1)Exercise price of options outstanding range from $2.12 to $11,160 as of March 31, 2023. The higher end of the range is due to the impact of several reverse stock splits during the years 2015 to 2018, subsequent to certain option grants, and relates to awards that expire during 2023.

As of March 31, 2023, the total unrecognized compensation expense, net of estimated forfeitures, relating to stock options was $11.6 million, which is expected to be recognized over the remaining weighted-average period of approximately 1.9 years.

Restricted stock. Non-vested restricted stock awards and the changes during the three months ended March 31, 2023, were as follows:


	Number of Shares	Weighted-Average Grant-Date Fair Value
Outstanding at December 31, 2022	5,254,457	$	3.94
Granted	89,334	$	1.89
Vested and issued	—	$	—
Canceled or forfeited	(7,295)	$	3.39

Non-vested at March 31, 2023	5,336,496	$	3.91

As of March 31, 2023, the total unrecognized compensation expense, net of estimated forfeitures, relating to restricted stock awards was $14.3 million, which is expected to be recognized over the remaining weighted-average period of approximately 1.8 years. As of March 31, 2023, there are no liability-classified restricted stock awards.