The Company maintains the MarketAxess Holdings Inc. 2020 Equity Incentive Plan (the “2020 Plan”), which provides for the grant of stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, or other stock-based awards as incentives to encourage employees, consultants and non-employee directors to participate in the long-term success of the Company. As of March 31, 2023, there were 2,442,744 shares available for grant under the 2020 Plan.

Total stock-based compensation expense was as follows:


	Three Months Ended March 31,
	2023		2022
	(In thousands)
Employees	$	7,100	$	7,642
Non-employee directors		388		457
Total stock-based compensation	$	7,488	$	8,099

The Company records stock-based compensation expense for employees in employee compensation and benefits and for non-employee directors in general and administrative expenses in the Consolidated Statements of Operations.

During the three months ended March 31, 2023, the Company granted a total of (i) 62,401 restricted stock units, (ii) 13,908 options to purchase shares of common stock and (iii) performance stock units with an expected pay-out at target of 18,263 shares of common stock. The fair values of the restricted stock units and performance stock units were based on a weighted-average fair value per unit at the grant date of $357.66 and $358.53, respectively. Based on the Black-Scholes option pricing model, the weighted-average fair value for each option granted was $123.47 per share.

As of March 31, 2023, the total unrecognized compensation cost related to all non-vested awards was $60.2 million. That cost is expected to be recognized over a weighted-average period of 1.7 years.

The Company maintains the MarketAxess Holdings Inc. 2022 Employee Stock Purchase Plan (the “ESPP”). The ESPP has a series of six-month offering periods, with a new offering period beginning on the first trading day on or after February 16 and August 16 of each year. Subject to certain limitations, employees may contribute up to $2,000 of such employee’s total eligible compensation per month towards the purchase of common stock via payroll deductions. Shares are purchased at a 15% discount off the lesser of: (i) the fair market value per share on the first day of each offering period; and (ii) the fair market value per share on the purchase date, but in no event less than par value. The Company issued 1,928 shares of common stock on February 15, 2023 under the ESPP. As of March 31, 2023, there were 119,293 shares available for purchase under the ESPP.