In 2021, the Company adopted the 2021 Omnibus Incentive Plan (the “2021 Plan”), which provides for the grant of restricted stock awards, incentive and nonqualified stock options, and other share based awards to employees, directors and non-employees. The 2021 Plan authorized 8,850,000 new shares of the Company’s common stock to be available for award grants. As of September 26, 2021, 6,797,101 shares of common stock remained available for future issuance under the 2021 Plan.

Equity-based compensation expense included the following components:


	For the thirteen weeks ended				For the thirty-nine weeks ended
	September 26, 2021		September 27, 2020		September 26, 2021		September 27, 2020
Stock options	$	376	$	—	$	376	$	—
Profit interest units		2,110		121		2,372		356

All equity-based compensation expense is recorded in selling, general and administrative costs in the condensed consolidated statements of comprehensive income.

Stock option grants have an exercise price at least equal to the market value of the underlying common stock on the date of grant, have ten-year terms, and vest ratably over three years of continued employment. In general, vested options expire if not exercised at termination of service. On July 16, 2021, the Company granted 1,394,008 options to purchase shares of the Company’s common stock to key employees. These stock options had a weighted-average grant date fair value $3.88 per share and remain outstanding and unvested as of September 26, 2021. Compensation expense for stock options is recorded based on straight-line amortization of the grant date fair value over the requisite service period.

As of September 26, 2021, there was $5,033 of unrecognized compensation cost related to unvested stock options that is expected to be recognized over a remaining weighted-average period of 2.8 years.

The fair value of each stock option granted on July 16, 2021 was estimated on the grant date using the Black-Scholes option pricing model with the following assumptions:


Weighted-average expected term		6.0
Expected volatility		40.3	%
Expected dividend	$	—
Risk-free interest rate		0.94	%

The expected term has been estimated using a simplified method, which calculates the expected term as the mid-point between the vesting date and the contractual life of the awards since the Company does not have an extended history of actual exercises. The expected dividend yield is assumed to be zero since the Company has never paid dividends and does not have current plans to pay any dividends. The risk-free interest rate is based on yields of U.S. Treasury securities with maturities similar to the expected term of the options. Expected volatility is based on an evenly weighted blend of implied volatility and historical volatility of publicly-traded peer companies since the Company has limited historical volatility.

Restricted stock units (“RSUs”) vest ratably over one to three years from the anniversary of the Closing Date, or July 16, 2021, and expire ten years from the date of grant. The fair value of a RSU at the grant date is equal to the market price of the Company’s common stock on the grant date. On September 23, 2021, the Company granted 658,891 RSUs to key employees and directors. These RSUs had a weighted-average grant date fair value of $12.06 per unit and remain outstanding and unvested as of September 26, 2021. Compensation expense for RSUs is recorded based on amortization of the grant date fair market value over the period the restrictions lapse,

As of September 26, 2021, there was $7,946 of unrecognized compensation cost related to unvested RSUs that is expected to be recognized over a remaining weighted average period of 2.5 years.

The Holley Stockholder made grants of 8,445 and 5,932 profit interest units (“PIUs”) to certain employees of the Company during the thirty-nine week periods ended September 26, 2021, and September 27, 2020, respectively. PIUs are a special type of limited liability company equity unit that allows the recipient to potentially participate in a future increase in the value of the Company. PIUs are issued for no consideration and generally provide for vesting over the requisite service period, subject to the recipient remaining an employee of the Company through each vesting date. The 2020 grants included 4,507 PIUs that contained certain performance vesting criteria related to the attainment of specified levels of return for certain other investors in Holley Stockholder. The weighted-average grant date fair value of these performance-based PIUs was $0.27 per unit. No expense has been recorded for the performance-based PIUs as meeting the necessary performance conditions for vesting is not considered probable.

As of September 26, 2021, there were 36,045 unvested PIUs with a weighted average grant date fair value of $0.64.

During the 39-week periods ended September 26, 2021 and September 27, 2020, 2,169 and 1,228 PIUs were fully vested, respectively, with a total grant-date fair value of $2,110 and $356 in 2021 and 2020, respectively. As of September 26, 2021, there was $15,999 of total unrecognized compensation cost related to unvested time-based PIUs that is expected to be recognized over a remaining weighted-average period of 1.9 years.