Stock-Based Compensation | 15. Stock-Based Compensation In September 2016, the Company adopted the 2016 Equity Compensation Plan (the “2016 Plan”) and merged the 2014 Equity Compensation Plan (the “2014 Plan”) into the 2016 Plan on September 28, 2016. No additional grants were made thereafter under the 2014 Plan. Outstanding grants under the 2014 Plan will continue in effect according to their terms as in effect before the merger with the 2016 Plan, and the shares with respect to outstanding grants under the 2014 Equity Plan will be issued or transferred under the 2016 Plan. The 2016 Plan authorizes the issuance or transfer of up to the sum of the following: (1) 800,000 new shares, plus (2) the number of shares of common stock subject to outstanding grants under the 2014 Equity Plan as of the effective date of the 2016 Plan; provided, however, that the aggregate number of shares of the Company’s common stock that may be issued or transferred under the 2016 Plan pursuant to incentive stock options may not exceed 800,000. During the term of the 2016 Plan, the share reserve will automatically increase on the first trading day in January of each calendar year, beginning in calendar year 2017, by an amount equal to the lesser of 5% of the total number of outstanding shares of common stock on the last trading day in December of the prior calendar year or such other number set by the Board. During 2018, in accordance with the terms of the 2016 Plan, the share reserve increased by 964,876 shares. As of March 31, 2018, 731,167 shares were available for future grants under the 2016 Plan. The option price per share cannot be less than the fair market value of a share on the date the option was granted, and in the case of incentive stock options granted to an employee owning more than 10% of the total combined voting power of all classes of stock of the Company, the option price shall not be less than 110% of the fair market value of Company stock on the date of grant. Stock option grants under the Plan generally expire 10 years from the date of grant, other than incentive stock option grants to 10% shareholders, which expire the earlier of 5 years from the date of grant, 90 days after termination, or one year after the date of death or termination due to disability. Stock options generally vest over a period of four years, with 25% of the options becoming exercisable on the one-year anniversary of the commencement date and the remaining shares vesting monthly thereafter for 36 months in equal installments of 2.08% per month. Employee Restricted Common Stock On September 28, 2016, the Board granted 700,386 shares of restricted common stock to certain Company employees, including executive officers, under the 2014 Plan, prior to merging it with the 2016 Plan, pursuant to a special equity award pool previously approved by the Board which was made immediately prior to the effectiveness of the Company's registration statement filed in connection with the Company's IPO. The value of the grants is based on the IPO price of $12.00 per share and the related non-cash compensation expense was recognized ratably over the vesting period from the date of grant through May 31, 2017, when the shares underlying the grant were scheduled to fully vest. For the three months ended March 31, 2017, $3,075 of expense was recognized related to this grant. No expense was recognized for the three months ended March 31, 2018. On June 12, 2017, the Company entered into an amendment with each recipient of this grant to amend the vesting date from May 31, 2017 to May 31, 2018. As of March 31, 2018, there was no unrecognized compensation expense related to this grant. On August 3, 2017, the Board granted 20,000 shares of restricted common stock to a non-executive employee of the Company, pursuant to the 2016 Plan, which will vest in four substantially equal annual installments over the four years following the grant date. The value of the grant is based on the grant date fair value of the Company’s common stock of $14.56 per share. On January 2, 2018, the Board granted 390,500 shares of restricted common stock to executive and certain non-executive employees of the Company, pursuant to the 2016 Plan, which will vest in four substantially equal annual installments over the four years following the grant date. The value of the grant is based on the grant date fair value of the Company’s common stock of $29.25 per share. On February 26, 2018, the Board granted 4,754 shares of restricted common stock to executive employees of the Company, pursuant to the 2016 Plan, which will vest one year following the grant date. The value of the grant is based on the grant date fair value of the Company’s common stock of $32.64 per share. For the three months ended March 31, 2018, $728 of expense was recognized related to these employee grants. As of March 31, 2018, there was unrecognized compensation expense of $11,111 related to these employee grants. Non-Employee Director Restricted Common Stock On September 28, 2016, the Company granted 22,260 shares of restricted common stock under the 2016 Plan to its non-employee directors, which represents both the initial and annual grants to such directors. The initial grant (“Initial Grant”) vests in three substantially equal annual installments over three years following the grant date and the annual grant of 7,420 shares vested in full on June 16, 2017, which was the date of the Company’s annual shareholder meeting. In addition, on September 28, 2017, 4,944 shares of the Initial Grant vested and were no longer subject to forfeiture. The value of the grants is based on the IPO price of $12.00 per share. On March 8, 2017, the Company granted 5,212 shares of restricted common stock under the 2016 Plan to a newly appointed non-employee director, which represents such director’s initial grant and will vest in three substantially equal annual installments over three years following the grant date. The value of the grant is based on the grant date fair value of the Company’s common stock of $13.68 per share. On June 16, 2017, the Company granted 10,384 shares of restricted common stock to its non-employee directors, which represents the annual grants to such directors, which will vest in full on the earlier of the next annual shareholder meeting or the one year anniversary of the grant date. The value of the grant is based on the grant date fair value of the Company’s common stock of $13.54 per share. On October 30, 2017, the Company granted 7,788 shares of restricted common stock to a non-employee director, which represents both the initial and annual grants to such director. The initial grant will vest in three substantially equal annual installments over three years following the grant date and the annual grant will vest in full on the earlier of the next annual shareholder meeting or August 3, 2018. The value of the grant is based on the grant date fair value of the Company’s common stock of $26.39 per share. For the three months ended March 31, 2018 and 2017, $82 and $56 of expense was recognized related to these non-employee director grants, respectively. As of March 31, 2018, there was unrecognized compensation expense of $289 related to these grants. Stock Options The Company recorded $1,135 and $690 of stock-based compensation expense related to the vesting of employee and non-employee stock options for the three months ended March 31, 2018 and 2017, respectively. The Company records forfeitures as they occur. The estimated fair value of options granted was calculated using a Black-Scholes option-pricing model. The computation of expected life for employees was determined based on the simplified method. The risk-free rate is based on the U.S. Treasury security with terms equal to the expected time of exercise as of the grant date. The Company's common stock had not been publicly traded until the IPO commenced on September 29, 2016; therefore, expected volatility is based on the historical volatilities of selected public companies whose services are comparable to that of the Company. The table below sets forth the weighted average assumptions for employee grants during the three months ended March 31, 2018 and 2017: Three Months Ended March 31, Valuation assumptions: 2018 2017 Expected volatility 58.40 % 61.00 % Expected term (years) 6.08 6.03 Risk-free interest rate 2.32 % 2.24 % Dividend yield — — The weighted average grant date fair value of employee options granted during the three months ended March 31, 2018 and 2017 was $16.46 and $7.89 per share, respectively. The following table summarizes stock option activity under the 2016 Plan for the three months ended March 31, 2018: Weighted Weighted average average remaining Aggregate Number exercise contractual intrinsic of shares price term value Outstanding at December 31, 2017 2,883,175 $ 9.26 Granted 384,500 Exercised (398,895) Forfeited (59,139) Outstanding at March 31, 2018 2,809,641 $ $ 73,778 Options vested and expected to vest at March 31, 2018 2,809,641 $ $ 73,778 Exercisable at March 31, 2018 1,385,167 $ $ 44,431 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the Company’s closing stock price or estimated fair value on the last trading day of the fiscal quarter for those stock options that had exercise prices lower than the fair value of the Company's common stock. This amount changes based on the fair market value of the Company’s stock. The total intrinsic value of options exercised during the three months ended March 31, 2018 and 2017 was $12,055 and $8,660, respectively. As of March 31, 2018, there was $13,799 of total unrecognized compensation cost related to nonvested stock options granted under the 2016 Plan, which is expected to be recognized over a weighted average period of 1.72 years. Cash received from option exercises for the three months ended March 31, 2018 and 2017 was $920 and $50, respectively. During the three months ended March 31, 2018, 23,991 shares of common stock were delivered by option holders as payment for the exercise price and employee payroll taxes owed for the exercise of 234,465 stock options with a gross exercise value of $819. During the three months ended March 31, 2017, 329,587 shares of common stock were delivered by option holders as payment for the exercise price and employee payroll taxes owed for the exercise of 776,422 stock options with a gross exercise value of $2,816. The Company recorded total stock-based compensation expense for the three months ended March 31, 2018 and 2017 in the following expense categories of its consolidated statement of operations: Three Months Ended March 31, 2018 2017 Cost of revenue - product $ 250 $ 95 Cost of revenue - service 270 43 Research and development 196 104 Sales and marketing 379 117 General and administrative 850 3,462 Total stock-based compensation expense $ 1,945 $ 3,821 |