Common Stock and Stockholders' Equity (Deficit) | Common Stock and Stockholders’ Equity (Deficit) Redeemable Convertible Preferred Stock Immediately prior to the completion of the IPO, all shares of redeemable convertible preferred stock then outstanding were converted into 41,273,345 shares of common stock on a one -to-one basis and then immediately reclassified into common stock. As of April 30, 2019 , there were no shares of redeemable convertible preferred stock issued and outstanding. Equity Incentive Plans 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 The 2019 Plan superseded and replaced the 2010 Plan. Under the 2019 Plan, the Company’s Board of Directors (the Board) and any other committee or subcommittee of the Board may grant stock options and restricted stock awards to employees, consultants, and advisors of the Company. Through April 30, 2019 , the Company has granted stock options and restricted stock awards. As of April 30, 2019 and January 31, 2019 the Company was authorized to grant up to 12,431,920 shares and 23,929,932 shares of common stock under the Stock Plans, respectively. Stock options generally have 10 -year terms and vest over four years from the option holder’s vesting commencement date with the Company and certain awards allow for early exercise. In March 2019, the Company granted 3,041,000 options to existing employees with 50 percent of these options vesting over four years from the grant date and 50 percent vesting over five years from the grant date. The Company currently uses authorized and unissued shares to satisfy stock award exercises. As of April 30, 2019 and January 31, 2019 , there were 12,431,920 shares and 2,221,216 shares available for future issuance under the Stock Plans. Stock Option Activity Stock option activity is as follows: Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in thousands) Balance at January 31, 2019 14,006,222 $ 4.32 8.2 years $ 142,840 Granted 3,682,821 $ 15.04 Exercised (951,830 ) $ 2.37 Forfeited (208,525 ) $ 6.13 Balance at April 30, 2019 16,528,688 $ 6.80 8.4 years $ 662,726 Vested as of April 30, 2019 5,743,831 $ 2.74 7.4 years $ 253,662 Stock options granted during the three months ended April 30, 2019 and 2018 had a weighted average grant date fair value of $10.58 and $3.63 per share, respectively. The aggregate intrinsic value of stock options exercised during the three months ended April 30, 2019 and 2018 was $19.9 million and $2.8 million , respectively. The intrinsic value for options exercised is the difference between the estimated fair value of the stock and the exercise price of the stock option at the date of exercise. Employee Stock Purchase Plan In April 2019, the Company’s board of directors adopted and approved the 2019 Employee Stock Purchase Plan, (ESPP), which became effective on April 11, 2019. The ESPP initially reserved and authorized the issuance of up to a total of 1,850,000 shares of common stock to participating employees. The initial offering period began April 11, 2019 and will end on June 15, 2021, with purchase dates of December 13, 2019, June 15, 2020, December 15, 2020 and June 15, 2021. 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, except for the initial offering period which began on April 11, 2019 and will end on December 15, 2019. 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. The Company recognized $0.4 million of stock-based compensation expense related to ESPP during the three months ended April 30, 2019 , beginning upon the IPO in April of 2019. As of April 30, 2019 , no amounts have been withheld on behalf of employees for a future purchase under the ESPP due to the timing of payroll deductions. There were no purchases for the three months ended April 30, 2019 related to the ESPP. Stock-Based Compensation 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, 2019 2018 Expected dividend yield — % — % Expected volatility 42.4% - 42.8% 40.9% - 41.0% Expected term (years) 5.5 - 6.9 5.8 - 6.1 Risk-free interest rate 2.32% - 2.48% 2.60% - 2.72% Stock-based compensation expense included in the Company’s condensed consolidated statements of operations is as follows (in thousands): Three Months Ended April 30, 2019 2018 Cost of revenue $ 143 $ 61 Research and development 860 715 Sales and marketing 1,464 852 General and administrative 2,345 1,529 Total $ 4,812 $ 3,157 As of April 30, 2019 and January 31, 2019 , there was approximately $64.2 million and $30.6 million of total unrecognized compensation cost related to unvested stock options granted under the Stock Plan, which will be recognized over a weighted average period of 3.7 years and 2.7 years, respectively. Warrant Issued as Charitable Contribution In fiscal 2019, the Company commenced an initiative to donate product, equity, and employee time for charitable purposes. In June 2018, as part of this initiative, the Company issued to the Tides Foundation a warrant to purchase up to 648,092 shares of the Company’s common stock, exercisable at a price of $0.01 per share. The common stock warrant was automatically net exercised for 647,822 |