Stockholders' Equity and Stock-Based Compensation | 8. Stockholders' Equity and Stock-Based Compensation Equity Compensation Plans In August 2021, the board of directors (the Board) adopted the 2021 Equity Incentive Plan (the 2021 Plan) and the 2021 Employee Stock Purchase Plan (ESPP), effective upon the IPO. Pursuant to the 2021 Plan, the Board may grant incentive stock options to purchase shares of the Company’s common stock, non-statutory stock options to purchase shares of the Company’s common stock, stock appreciation rights, restricted stock, restricted stock units (RSUs), performance awards (PRSUs) and other awards. The ESPP enables eligible employees to purchase shares of the Company's Class A common stock. Both the 2021 Plan and ESPP include an automatic increase to their shares reserve on January 1 of each year as set forth in the respective plan documents. In August 2022, the Compensation Committee of the Board adopted the 2022 Inducement Plan (the Inducement Plan) in accordance with Listing Rule 5635(c)(4) of the Nasdaq Stock Market. Under the Inducement Plan, nonstatutory stock options, stock appreciation rights, restricted stock, RSUs, PRSUs and other awards may be granted as an inducement material to an eligible person's entering into employment with the Company. Shares of common stock reserved for future issuance were as follows (in thousands): September 30, 2023 2011 Stock Plan: Options, RSUs and PRSUs outstanding 14,418 2021 Equity Incentive Plan: Options and RSUs outstanding 14,318 Shares reserved for future award issuances 64,223 2022 Inducement Plan: Options and RSUs outstanding 3,076 Shares reserved for future award issuances 6,700 2021 Employee Stock Purchase Plan Shares reserved for future award issuances 10,798 Total shares of common stock reserved for issuance 113,533 2021 Employee Stock Purchase Plan Under the ESPP, the price at which common stock is purchased is equal to 85% of the fair market value of a share of the Company’s common stock on the first day of the offering period or the applicable purchase date, whichever is lower. The fair market value of common stock will generally be the closing sales price on the determination date. The ESPP provides an offering period of 24 months, with four purchase periods that are generally six months long and end on May 15 and November 15 of each year, except for the first purchase period, which began upon the completion of the IPO in September 2021 and ended on May 13, 2022. During the nine months ended September 30, 2023 and September 30, 2022, the Company issued 367,319 and 510,093 shares under the ESPP, respectively, in each case net of shares withheld and retired to satisfy withholding tax requirements for certain employees in jurisdictions outside the United States. The weighted average purchase price was $11.87 with net proceeds of $4.3 million in the nine months ended September 30, 2023, and the weighted average purchase price was $13.76 with net proceeds of $7.0 million in the nine months ended September 30, 2022. The ESPP also includes a reset provision for the purchase price if the fair market value of a share of the Company's common stock on the first day of any purchase period is less than or equal to the fair market value of a share of the Company's common stock on the first day of an ongoing offering. If the reset provision is triggered, a new 24-month offering period begins. The reset provision under the ESPP was triggered on May 16, 2022, and again on November 16, 2022. Each triggering of the reset provision was considered a modification in accordance with ASC 718, Stock Based Compensation , with the modification charge recognized on a straight-line basis over the new offering period. The previous modifications did not have a material effect on the Company's stock-based compensation expense during the three and nine months ended September 30, 2023. Stock-based compensation expense related to ESPP was $1.5 million and $2.2 million for the three months ended September 30, 2023 and 2022, respectively, and $6.0 million and $9.4 million for the nine months ended September 30, 2023 and 2022, respectively. Determination of Fair Value of the ESPP The Company estimates the fair value of the ESPP using the Black-Scholes option-pricing model, which requires certain complex valuation assumption inputs such as expected term, expected stock price volatility, risk-free interest rate, and dividend yield. The fair value of each of the four purchase periods is estimated separately. The following table summarizes the range of valuation assumptions used in estimating the fair value of the ESPP during the period: Valuation Assumption Inputs Nine Months Ended September 30, 2023 Nine Months Ended September 30, 2022 Expected term (in years) 0.5 - 1.5 0.5 - 2.0 Stock price volatility 58.1% - 77.3% 55.8% - 84.5% Risk-free interest rate 4.47% - 5.26% 1.54% - 2.58% Dividend yield —% —% Stock Options Stock options are generally granted with an exercise price equal to the fair market value of a share of common stock on the date of grant, have a 10-year contractual term, and vest over a four-year period. Share Information: Number of Shares (in thousands) Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) (1) Balance as of December 31, 2022 2,758 $ 9.06 7.3 $ 15,595 Stock options exercised (205) $ 0.30 Stock options cancelled / forfeited / expired (3) $ 0.16 Balance as of September 30, 2023 2,550 $ 9.77 6.9 $ 25,883 Options vested and expected to vest as of September 30, 2023 2,550 $ 9.77 6.9 $ 25,883 Options exercisable as of September 30, 2023 1,188 $ 5.37 4.6 $ 17,289 (1) Aggregate intrinsic value for stock options represents the difference between the exercise price and the per share fair value of the Company’s common stock as of the end of the period, multiplied by the number of stock options outstanding, exercisable, or vested. Restricted Stock Units RSUs are granted at fair market value at the date of the grant and typically vest over a four-year period. RSU activity, which includes PRSUs, during the nine months ended September 30, 2023 is as follows: Share Information: Number of Shares Weighted-Average Grant Date Fair Value Per Share (in thousands, except per share data) Unvested, as of December 31, 2022 32,253 $ 18.86 Granted 9,164 $ 14.04 Vested (1) (8,350) $ 16.42 Forfeited (3,805) $ 17.31 Unvested, as of September 30, 2023 29,262 $ 18.25 (1) During the nine months ended September 30, 2023, total shares that vested were 8.3 million, of which 3.2 million were withheld for tax purposes. The total fair value of vested RSUs during the three months ended September 30, 2023 and 2022 was $50.7 million and $42.4 million, respectively. For the nine months ended September 30, 2023 and 2022, the total fair value of vested RSUs was $137.1 million and $191.4 million, respectively. Performance-Based Awards In May 2019, the Board approved a grant of 166,390 shares of PRSUs to the Company’s Chief Executive Officer (CEO). The vesting of these PRSUs is contingent upon the satisfaction of certain milestones. The revenue-related milestone and the liquidity event condition were met prior to December 31, 2021. As of September 30, 2023, the time-based vesting was the only condition yet to be satisfied over the remaining requisite service period, and the number of shares to vest subject to this condition is insignificant. In September 2021, the Board approved a grant of 6,000,000 PRSUs to the Company's CEO with a time-based service condition beginning January 1, 2022, and a market condition involving five separate stock price targets ranging from $70.00 to $200.00 per share for each of the five vesting tranches (CEO Performance Award). These stock price targets will be measured based on the average closing price over a consecutive 60-trading day period, beginning on the first trading day after the expiration of the final lock-up period in February 2022. The vesting of the CEO Performance Award is contingent upon the completion of the requisite service through January 1, 2029 and the achievement of the specified stock price target in each tranche on or before January 1, 2029. The stock price targets are not required to be achieved within the service period of each tranche, and accordingly, multiple tranches can vest at the same date if the specified stock price targets are achieved after December 31, 2025. The CEO Performance Award had a total grant date fair value of $131.0 million. The fair value of the CEO Performance Award was determined at grant date by using the Monte Carlo simulation model, which requires certain complex valuation assumption inputs such as measurement period, expected stock price volatility, risk-free interest rate and dividend yield. The Company recognized stock-based compensation expense associated with PRSUs granted to the CEO of $7.1 million for each of the three months ended September 30, 2023 and 2022; and $21.0 million each for the nine months ended September 30, 2023 and 2022. These expenses were recorded in general and administrative expenses in the condensed consolidated statements of operations. Stock-Based Compensation Total stock-based compensation expense recorded for the three and nine months ended September 30, 2023 and 2022 was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2023 2022 2023 2022 Cost of revenue $ 1,710 $ 1,772 $ 5,137 $ 5,212 Research and development 9,623 10,318 28,662 26,446 Sales and marketing (1) 18,757 16,635 51,786 44,204 General and administrative (2) 25,035 25,167 74,482 74,790 Stock-based compensation, net of amounts capitalized 55,125 53,892 160,067 150,652 Capitalized stock-based compensation 484 52 1,422 1,275 Total stock-based compensation expense $ 55,609 $ 53,944 $ 161,489 $ 151,927 (1) Sales and marketing expense includes $2.4 million and $7.1 million for the three and nine months ended September 30, 2023, respectively, of stock-based compensation expense related to RSUs, options and ESPP purchase rights granted to the President of the Company primarily granted in September 2022. Stock-based compensation expense related to awards granted to the President were not material during the three and nine months ended September 30, 2022. (2) General and administrative expense includes stock-based compensation expense associated with RSUs and PRSUs granted to our CEO primarily in September 2021 of $14.1 million for each of the three months ended September 30, 2023 and 2022, and $41.8 million for each of the nine months ended September 30, 2023 and 2022. As of September 30, 2023, unrecognized stock-based compensation expense related to unvested stock-based awards was as follows (in thousands, except for period data): September 30, 2023 Unrecognized Stock-Based Compensation Weighted-Average Period to Recognize Expense RSUs and PRSUs $ 441,719 2.8 Stock options 10,955 2.9 ESPP 5,750 0.8 Total unrecognized stock-based compensation expense $ 458,424 |