Our share-based compensation consists of performance-based stock options, term-based stock options, restricted stock units (“RSUs”), and performance-based stock units (“PSUs”). We also offer an employee stock purchase plan.

Prior to November 1, 2013, Ceridian employees participated in a share-based compensation plan of the former ultimate parent of Ceridian, the 2007 Stock Incentive Plan (“2007 SIP”). Effective November 1, 2013, although most participants who held stock options under the 2007 SIP converted their options to a newly created option plan, the 2013 Ceridian HCM Holding Inc. Stock Incentive Plan, as amended (“2013 SIP”), a small number of participants maintained their stock options in the 2007 SIP. Concurrent with the initial public offering (“IPO”) and legal reorganization, all outstanding stock options under the 2007 SIP were converted into options to purchase common stock of Ceridian. As of March 31, 2021, there were 1,936 stock options outstanding under the 2007 SIP.

Stock options awarded under the 2013 SIP vest either annually on a pro rata basis over a four- or five-year period or on a specific date if certain performance criteria are satisfied and certain equity values are attained. In addition, upon termination of service, all vested options must be exercised generally within 90 days after termination, or these awards will be forfeited. The stock option awards have a 10-year contractual term and have an exercise price that is not less than the fair market value of the underlying stock on the date of grant. As of March 31, 2021, there were 2,050,635 stock options and RSUs outstanding under the 2013 SIP. We do not intend to grant any additional awards under the 2007 SIP or the 2013 SIP.

On April 24, 2018, in connection with our initial public offering, the Board of Directors and our stockholders approved the Ceridian HCM Holding Inc. 2018 Equity Incentive Plan (“2018 EIP”), which authorized the issuance of up to 13,500,000 shares of common stock to eligible participants through equity awards (the “Share Reserve”). The Share Reserve may be increased on March 31 of each of the first ten calendar years during the term of the 2018 EIP, by the lesser of (i) three percent of the number of shares of our common stock outstanding on each January 31 immediately prior to the date of increase or (ii) such number of shares of our common stock determined by the Board of Directors. Effective on March 31, 2021, the Share Reserve was increased by 4,397,296 shares, pursuant to the terms of the 2018 EIP.

Equity awards under the 2018 EIP vest either annually or quarterly on a pro rata basis, generally over a one-, three-, or four-year period. In addition, upon termination of service, all vested awards must be exercised within 90 days after termination, or these awards will be forfeited. The equity awards have a 10-year contractual term and have an exercise price that is not less than the fair market value of the underlying stock on the date of the grant. As of March 31, 2021, there were 13,284,080 stock options, RSUs, and PSUs outstanding and 13,008,498 shares available for future grants of equity awards under the 2018 EIP.

Total share-based compensation expense was $22.8 million and $12.5 million for the three months ended March 31, 2021, and 2020, respectively.

Performance-based stock option activity under the 2007 SIP, the 2013 SIP, and the 2018 EIP was as follows:

	Shares			Weighted Average Exercise Price (per share)			Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Performance-based options outstanding at December 31, 2020		1,844,279		$	64.55			9.2	$	77.5
Granted		—			—			—		—
Exercised		(2,500	)		(13.46	)		—		—
Forfeited or expired		—			—			—		—
Performance-based options outstanding at March 31, 2021		1,841,779		$	64.62			9.0	$	36.2
Performance-based options exercisable at March 31, 2021		23,051		$	13.81			1.4	$	1.6

In 2020, 1,500,000 performance-based stock options (“Performance Option Award”) were granted under the 2018 EIP with an exercise price of $65.26. The vesting conditions for the Performance Option Award are based on the Company’s performance on the New York Stock Exchange (“NYSE”) with 750,000 shares available to vest when the Company’s per share closing price on the NYSE meets or exceeds $110.94, or 1.7 times the exercise price, for ten consecutive trading days, and the remaining 750,000 shares are available to vest when the Company’s per share closing price on the NYSE meets or exceeds $130.52, or 2.0 times the exercise price, for ten consecutive trading days. The Performance Option Award has a minimum time-based vesting period of 3 years. The vesting conditions must be achieved prior to May 8, 2025, or any unvested portion of the Performance Option Award will terminate. A Monte Carlo simulation model was used to determine the fair value of these performance-based stock options. The Monte Carlo model utilizes multiple input variables that determine the probability of satisfying the market conditions stipulated in the award. We have estimated an expected term of 5.3 years, based on the vesting period and contractual term.

As of March 31, 2021, there was $22.4 million of share-based compensation expense related to unvested performance-based stock option awards not yet recognized, which is expected to be recognized over a weighted average period of 3.0 years.

Term-based stock option activity under the 2007 SIP, the 2013 SIP, and the 2018 EIP was as follows:

	Shares			Weighted Average Exercise Price (per share)			Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Term-based options outstanding at December 31, 2020		10,983,074		$	40.47			7.8	$	725.9
Granted		399,388			80.95			—		—
Exercised		(273,516	)		(28.82	)		—		—
Forfeited or expired		(30,061	)		(51.12	)		—		—
Term-based options outstanding at March 31, 2021		11,078,885		$	42.19			7.7	$	466.4
Term-based options exercisable at March 31, 2021		4,227,029		$	32.90			7.0	$	217.0

As of March 31, 2021, there was $87.2 million of share-based compensation expense related to unvested term-based stock options not yet recognized, which is expected to be recognized over a weighted average period of 1.8 years.

	Shares
RSUs outstanding at December 31, 2020		1,389,385
Granted		720,854
Shares issued upon vesting of RSUs		(27,207	)
Forfeited or canceled		(3,166	)
RSUs outstanding at March 31, 2021		2,079,866
RSUs releasable at March 31, 2021		556,892

During the three months ended March 31, 2021, 160,620 RSUs vested. As of March 31, 2021, there were 1,522,974 unvested RSUs outstanding and 556,892 vested RSUs outstanding. As of March 31, 2021, there was $95.1 million of share-based compensation expense related to unvested RSUs not yet recognized, which is expected to be recognized over a weighted average period of 1.8 years.

	Shares
PSUs outstanding at December 31, 2020		135,220
Granted		336,214
Shares issued upon vesting of PSUs		—
Forfeited or canceled		(135,313	)
PSUs outstanding at March 31, 2021		336,121
PSUs releasable at March 31, 2021		—

The vesting conditions for the PSUs granted in 2020 were based on the Company’s performance criteria, including Cloud revenue and adjusted EBITDA margin goals under Ceridian HCM Holding Inc. 2020 Management Incentive Plan (the “2020 MIP”) for the incentive period of January 1, 2020 through December 31, 2020. The vesting conditions for the PSUs granted in connection with the 2020 MIP were not met for the incentive period and as a result, the PSUs did not vest and were cancelled.

The vesting conditions for the PSUs granted in 2021 are based on the Company’s performance criteria, including Cloud revenue and adjusted EBITDA margin goals under Ceridian HCM Holding Inc. 2021 Management Incentive Plan (the “2021 MIP”) for the incentive period of January 1, 2021 through December 31, 2021. The maximum incentive vesting of PSUs may not exceed 150% under the 2021 MIP. Both the Cloud revenue and adjusted EBITDA margin goals are calculated based on the Company’s operating results, adjusted for foreign currency and interest rate impacts plus other unique impacts as approved by the Compensation Committee or the Board of Directors. Upon vesting of a PSU, a participant will receive shares of common stock of the Company. The probability

of vesting of PSUs will continue to be evaluated throughout the period, and share-based compensation expense will be recognized in accordance with that probability. As of March 31, 2021, there was $23.6 million of share-based compensation expense related to unvested PSUs not yet recognized.

On November 9, 2018, the Board of Directors approved the Ceridian HCM Holding Inc. Global Employee Stock Purchase Plan (“GESPP”), and the Company’s stockholders approved the GESPP on May 1, 2019. The GESPP authorizes the issuance of up to 2,500,000 shares of common stock to eligible participants through purchases via payroll deductions. A total of 2,015,544 shares of common stock are available for future issuances under the plan at March 31, 2021. The purchase price is the lower of (i) 85% of the fair market value of a share of common stock on the offering date (the first trading day of the offering period commencing on January 1 and concluding on December 31) or (ii) 85% of the fair market value of a share of common stock on the purchase date. The GESPP shall continue for ten years, unless terminated sooner as provided under the GESPP. Quarterly purchase periods commence on January 1, April 1, July 1, and October 1 and shares are purchased on the last trading day of the respective purchase periods.