The Company has two equity incentive plans: the 2010 Stock Plan (the “2010 Plan”) and the 2019 Equity Incentive Plan (the “2019 Plan”, collectively the “Stock Plans”). Upon completion of the Company’s IPO in April 2019, the Company ceased granting awards under the 2010 Plan, and all shares that remained available for future issuance under the 2010 Plan at that time were transferred to the 2019 Plan. The 2019 Plan superseded and replaced the 2010 Plan. As of April 30, 2021 and January 31, 2021, respectively, the Company was authorized to grant up to 22,233,800 shares and 18,059,506 shares of common stock under the Stock Plans.

The Company currently uses authorized and unissued shares to satisfy stock award exercises. As of April 30, 2021 and January 31, 2021, there were 15,344,651 shares and 13,060,282 shares available for future issuance under the Stock Plans, respectively.


			April 30, 2021
Outstanding stock options and unvested RSUs and PSUs outstanding			16,170,681
Available for future stock option, RSU, and PSU grants			15,344,651
Available for ESPP			2,944,123
Total common stock reserved at April 30, 2021			34,459,455


	Number of Shares	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
					(in thousands)
Outstanding at January 31, 2021	11,177,838	$	8.25	6.9 years	$	452,452
Granted	32,428	$	41.17
Exercised	(536,593)	$	5.23
Canceled	(40,185)	$	9.09
Outstanding at April 30, 2021	10,633,488	$	8.50	6.7 years	$	361,089
Vested as of April 30, 2021	7,447,293	$	6.00	6.2 years	$	271,497

The Company uses the Black-Scholes option-pricing model to estimate the fair value of stock options on the date of grant. The Company accounts for forfeitures as they occur. The following assumptions were used to calculate the fair value of employee stock option grants made during the periods:


	Three Months Ended April 30,
	2021		2020
Expected dividend yield	—	%	—	%
Expected volatility	43.8%		43.3	%
Expected term (years)	6.1		6.1
Risk-free interest rate	1.16%		0.46% - 0.47%

Stock options granted during the three months ended April 30, 2021 and 2020 had a weighted average grant date fair value of $17.80 and $6.61 per share, respectively. The aggregate intrinsic value of stock options exercised during the three months ended April 30, 2021 and 2020 was $20.5 million and $11.5 million, respectively.

The intrinsic value for options exercised is the difference between the market value of the stock and the exercise price of the stock option at the date of exercise.

As of April 30, 2021 there was approximately $29.0 million of total unrecognized compensation cost related to unvested stock options granted under the Stock Plans, which will be recognized over a weighted average period of 2.5 years.


	Number of RSUs	Weighted Average Grant Date Fair Value Per Share
Outstanding at January 31, 2021	3,971,128	$	23.60
Granted	1,839,607	$	41.17
Vested	(174,135)	$	18.48
Canceled	(226,716)	$	24.10
Outstanding at April 30, 2021	5,409,884	$	29.72

The Company uses the fair value of RSUs based on the fair value of the underlying shares on the date of grant. The Company accounts for forfeitures as they occur.

As of April 30, 2021, there was $151.5 million of unrecognized stock-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted average period of 3.5 years based on vesting under the award service conditions.

In April 2021, the Company granted 127,309 PSUs, with a weighted-average grant date fair value of $41.17, to certain employees of the company for which the ultimate number of stock units that will vest are determined based on the achievement of performance at the end of the stated performance period. The performance condition is based on the level of achievement of a Company target related to PagerDuty’s operating plan for the fiscal year 2022 ("2022 operating plan"). The PSUs will vest over a three-year period, subject to continuous service with the Company.

As of April 30, 2021, the Company recorded stock-based compensation expense for the number of PSUs considered probable of vesting based on the expected attainment of the performance targets.

As of April 30, 2021, total unrecognized stock-based compensation cost related to PSUs was $4.6 million. This unrecognized stock-based compensation cost is expected to be recognized using the accelerated attribution method over a weighted-average period of approximately 1.7 years.

In April 2019, the Board of Directors adopted and approved the 2019 Employee Stock Purchase Plan, which became effective on April 11, 2019. The ESPP generally provides for 24-month offering periods beginning June 15 and December 15 of each year, with each offering period consisting of four six-month purchase periods. On each purchase date, eligible employees will purchase the shares at a price per share equal to 85% of the lesser of (1) the fair market value of the Company’s stock as of the beginning of the offering period or (2) the fair market value of the Company’s stock on the purchase date, as defined in the ESPP.

During the three months ended April 30, 2021 and 2020, the Company recognized $1.8 million and $1.6 million of stock-based compensation expense related to the ESPP, respectively.

During the three months ended April 30, 2021 and 2020, the Company withheld $3.0 million and $1.9 million in contributions from employees, respectively.


	Three Months Ended April 30,
	2021		2020
	(in thousands)
Cost of revenue	$	676	$	344
Research and development	4,440		2,183
Sales and marketing	3,954		2,285
General and administrative	4,542		3,496
Total	$	13,612	$	8,308