The Company maintains the MarketAxess Holdings Inc. 2020 Equity Incentive Plan (the “2020 Plan”), which provides for the grant of restricted stock, restricted stock units, performance shares, performance stock units (collectively, “full value awards”), stock options and 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 June 30, 2024, there were 2,468,562 shares available for grant under the 2020 Plan.

Total stock-based compensation expense was as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
	(In thousands)
Employees	$	7,929	$	6,647	$	14,822	$	13,747
Non-employee directors		399		243		804		631
Total stock-based compensation	$	8,328	$	6,890	$	15,626	$	14,378

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. Total stock-based compensation for employees includes $0.3 million and $0.2 million of capitalized software development costs for the three months ended June 30, 2024 and 2023, respectively, and $0.5 million and $0.4 million of capitalized software development costs for the six months ended June 30, 2024 and 2023, respectively.

During the six months ended June 30, 2024, the Company granted (i) 143,975 restricted stock units, (ii) 20,793 stock options and (iii) performance stock units with an expected pay-out at target of 32,608 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 $218.48 and $219.32, respectively. The weighted-average fair value for stock options of $77.16 per share was based on the Black-Scholes option pricing model.

As of June 30, 2024, the total unrecognized compensation cost related to all non-vested awards was $60.7 million. That cost is expected to be recognized over a weighted-average period of 2.2 years.

The Company maintains the MarketAxess Holdings Inc. 2022 Employee Stock Purchase Plan (the “ESPP”), pursuant to which a total of 121,221 shares of the Company’s common stock is available for purchase by employees. The Company issued 3,756 shares of common stock on February 15, 2024 under the ESPP. As of June 30, 2024, there were 112,810 shares available for purchase under the ESPP.