13.  Equity Incentive Plans and Stock-Based Compensation

Prior Stock Plans

In June 2015, we adopted our 2015 Stock Plan (the “2015 Plan”). The 2015 Plan was terminated in June 2018 in connection with the adoption of the 2018 Plan. Accordingly, no shares are available for future issuances under the 2015 Plan following the adoption of the 2018 Plan.

In June 2018, we adopted the 2018 Plan, which provides for grants of stock-based awards, including RSUs, RSAs, and stock options. The 2018 Plan was terminated in April 2021 in connection with the adoption of our 2021 Stock Plan (the “2021 Plan”). Accordingly, no shares are available for future issuances under the 2018 Plan following the adoption of the 2021 Plan.

2021 Stock Plan

In April 2021, prior to and in connection with the IPO, we adopted the 2021 Plan, which provides for grants of incentive stock options, nonstatutory stock options, stock appreciation rights, RSAs, RSUs, performance awards, and other forms of awards. We have reserved 118.8 million shares of our Class A common stock to be issued under the 2021 Plan. In addition, the number of shares of our Class A common stock reserved for issuance under the 2021 Plan will automatically increase on February 1 of each year for a period of ten years, beginning on February 1, 2022 and continuing through February 1, 2031, in an amount equal to (1) 5% of the total number of shares of our common stock (both Class A and Class B) outstanding on the preceding January 31, or (2) a lesser number of shares determined by our board of directors no later than the February 1 increase.

2021 Employee Stock Purchase Plan

In April 2021, prior to and in connection with the IPO, we adopted our 2021 Employee Stock Purchase Plan (the “2021 ESPP”). The 2021 ESPP authorizes the issuance of 10.5 million shares of our Class A common stock under purchase rights granted to our employees or to employees of any of our designated affiliates. The number of shares of our Class A common stock reserved for issuance will automatically increase on February 1 of each year for a period of ten years, beginning on February 1, 2022 and continuing through February 1, 2031, by the lesser of (i) 1% of the total number of shares of our common stock (both Class A and Class B) outstanding on the preceding January 31; and (ii) 15.5 million shares, except before the date of any such increase, our board of directors may determine that such increase will be less than the amount set forth in clauses (i) and (ii) above.  The initial offering period began on April 21, 2021, and the first purchase date will fall on December 20, 2021.

Stock Options

The following table summarizes the option activity under our stock plans during the reporting period:

The weighted-average grant date fair value of stock options granted during the three months ended April 30, 2021 and 2020 was $55.91 and $5.25 per share, respectively. The intrinsic value of stock options exercised during the three months ended April 30, 2021 and 2020 was $101.0 million and $21.8 million, respectively.

During the three months ended April 30, 2021 and 2020, our compensation committee approved certain modifications to stock options, including acceleration of the service-based vesting condition of certain employee stock options upon termination and extension of exercise period of certain outstanding employee stock options. Incremental expense associated with these modifications was immaterial and $2.2 million for the three months ended April 30, 2021 and 2020, respectively.

Unrecognized compensation expense associated with unvested stock options granted and outstanding as of April 30, 2021, was $99.8 million, which is to be recognized over a weighted-average remaining period of 2.6 years.

Early Exercised Options

Certain stock option holders have the right to exercise unvested options, subject to a repurchase right held by us at the original exercise price, in the event of voluntary or involuntary termination of employment of the option holders, until the options are fully vested. As of April 30, 2021, there were outstanding 1.7 million shares underlying unvested stock options that had been early exercised. The cash proceeds associated with these early exercises are recorded within accrued expenses and other current liabilities and other liabilities, non-current in our condensed consolidated balance sheets, depending upon the future vesting dates of the associated options. Such accrued amounts totaled $4.2 million and $5.9 million as of April 30, 2021 and January 31, 2021, respectively. Proceeds are transferred to additional paid-in capital at the time of option vesting.

Restricted Stock Units

RSU activity during the three months ended April 30, 2021 consisted of the following (in thousands except per share amounts):

The fair value of RSUs vested during the three months ended April 30, 2021 and 2020 was $1,003.6 million and none, respectively.

Prior to the IPO, the Company granted RSUs which vested on the satisfaction of both a service-based condition and a performance-based condition. The performance-based vesting condition was deemed satisfied on April 23, 2021, the date that the Company completed the IPO. Upon closing of the IPO, the Company recognized $233.0 million of cumulative stock-based compensation expense for the portion of these RSUs for which the service-based vesting condition had been fully or partially satisfied.

During the three months ended April 30, 2021, our compensation committee approved a modification to allow acceleration of vesting of 0.2 million RSUs, resulting in the recognition of $8.9 million of incremental expense. Incremental expense associated with modifications of RSUs was insignificant for the three months ended April 30, 2020.

As of April 30, 2021, total unrecognized compensation expense related to unvested RSUs was approximately $288.2 million and will be recognized over a weighted-average remaining period of 3.3 years.

Restricted Stock Awards

In September 2020, we issued approximately 0.1 million RSAs to a member of our board of directors at a grant date fair value of $33.22 per share, totaling $4.0 million. Such RSAs vest monthly over four years from the grant date. The unvested shares are subject to a repurchase right held by us at the original purchase price. As of April 30, 2021, total unrecognized compensation expense related to unvested RSAs was $3.4 million and will be recognized over the remaining vesting period of 3.4 years.

Tax Withholdings on Employee Equity Transactions

For the majority of our tax jurisdictions, we have adopted sell-to-cover as the tax withholding method for equity awards upon settlement, pursuant to which shares with a market value equivalent to the tax withholding obligations are sold on behalf of the holder of the awards to cover the tax withholding liability, and the cash proceeds from such sales are remitted by the Company to taxing authorities. For certain other tax jurisdictions where selling restrictions exist, the Company may issue net shares and remit tax liabilities to the relevant tax authorities on behalf of the award holders, or may accept employee payment of tax withholdings in cash.

Stock-based Compensation Expense

We classified stock-based compensation expense in the condensed consolidated statements of operations as follows (in thousands):

The expense presented in the above table is net of capitalized stock-based compensation relating to software development costs of $2.2 million for the three months ended April 30, 2021. Capitalized stock-based compensation relating to software development costs for the three months ended April 30, 2020 was immaterial.