Stock-Based Compensation Plans

9 Months Ended

Sep. 30, 2022

Share-Based Payment Arrangement, Noncash Expense [Abstract]

The components of stock-based compensation expense were as follows:


	Three months ended September 30,				Nine months ended September 30,
	2022		2021		2022		2021
	(in thousands)				(in thousands)
2007 Stock Incentive Plan	$	—	$	9	$	—	$	1,651
2021 Stock Incentive Plan	3,098		4,517		10,732		10,023
Employee Stock Purchase Plan	48		51		84		201
Total Stock Compensation Expense	$	3,146	$	4,577	$	10,816	$	11,875

The significant stock compensation plans are described below.

The 2007 Stock Incentive Plan (the “2007 Plan”) was adopted in May 2007. Under the 2007 Plan, a total of 2,800,000 shares were authorized for stock-based compensation available in the form of either restricted stock awards (“RSAs”) or stock options. The RSAs are subject to service-based vesting, typically between one and four years, where a specific period of continued employment must pass before an award vests. The expense associated with these awards is recognized on a straight-line basis over the respective vesting period, with forfeitures accounted for as they occur. For any vesting tranche of an award, the cumulative amount of compensation cost recognized is equal to the portion of the grant‑date fair value of the award tranche that is actually vested at that date. As of September 30, 2022, there were no stock options outstanding under the 2007 Plan.

The 2018 Stock Incentive Plan (the “2018 Plan”) was adopted in May 2018. Under the 2018 Plan, a total of 800,000 shares were authorized for stock-based compensation, plus the number of shares remaining under the 2007 Plan and any future forfeited awards under the 2007 Plan, in the form of RSAs. In November 2021, the 2018 Plan was amended and restated as the 2021 Stock Incentive Plan (the “2021 Plan”) to increase the number of shares reserved for issuance under the 2021 Plan by 1,000,000 shares. The RSAs are subject to service and performance-based vesting, typically between one and four years, where a specific period of continued employment or service must pass before an award vests. The expense associated with these awards is recognized on a straight-line basis over the respective vesting period, with forfeitures accounted for as they occur. For any vesting tranche of an award, the cumulative amount of compensation cost recognized is equal to the portion of the grant‑date fair value of the award tranche that is actually vested at that date.

As of September 30, 2022, the Company had granted 1,256,700 RSAs under the 2021 Plan and had 637,896 shares available for future issuance. The fair value of the restricted stock awards equaled the stock price at the grant date.

The following table summarizes the restricted stock activity during the nine months ended September 30, 2022:


			Shares
Balance of unvested shares as of December 31, 2021			560,608
Shares granted			330,400
Shares forfeited			—
Shares vested			(368,810)
Balance of unvested shares as of September 30, 2022			522,198

Under the Employee Stock Purchase Plan (“ESPP”), as amended and restated effective November 10, 2021, 425,000 shares of common stock have been reserved for issuance. Eligible employees may designate no more than 10% of their base cash compensation to be deducted each pay period for the purchase of common stock under the ESPP. Participants may purchase no more than 1,000 shares or $25,000 of common stock in any one calendar year. Each January 31 and July 31, shares of common stock are purchased with the employees’ payroll deductions from the immediately preceding six months at a price per share of 85% of the lesser of the market price of the common stock on the purchase date or the market price of the common stock on the date of entry into an offering period. During the nine months ended September 30, 2022 and 2021, 19,789 and 18,211 shares of common stock, respectively, were issued under the ESPP. The Company issues new shares through its transfer agent upon an employee stock purchase.