Common Stock | 8. Common Stock Stock Options Activity under the Company’s stock option plan is set forth below: Weighted- Weighted Average Average Remaining Aggregate Exercise Contractual Intrinsic Value Number of Shares Price Term (Years) (in thousands) Balance—December 31, 2016 2,906,596 $ 3.20 8.1 $ 4,941 Granted 1,320,382 $ 7.08 Exercised (388,621 ) $ 3.28 Canceled (104,813 ) $ 4.53 Balance—December 31, 2017 3,733,544 $ 4.53 7.9 $ 25,386 Granted — $ — Exercised (3,466 ) $ 3.68 Canceled (92,830 ) $ 5.64 Balance—March 31, 2018 3,637,248 $ 4.47 7.3 $ 1,899 Vested and exercisable—March 31, 2018 1,852,907 $ 3.10 6.0 $ 23,353 Vested and exercisable—December 31, 2017 1,648,917 $ 2.89 6.7 $ 13,924 As of March 31, 2018, approximately $4.6 million of unrecognized stock compensation costs related to awards were expected to be recognized over a weighted-average period of 2.6 years. As of December 31, 2017, approximately $4.8 million of unrecognized stock compensation costs related to awards were expected to be recognized over a weighted-average period of 3.1 years. The aggregate intrinsic value of options exercised during the three months ended March 31, 2018 was $0.1 million. The aggregate intrinsic value of options exercised during the year ended December 31, 2017 was $1.6 million. There were no options granted during the three months ended March 31, 2018. The weighted-average grant-date fair value of options granted during the year ended December 31, 2017 was $2.94 per share. The calculated fair value of option grants was estimated using the Black-Scholes model with the following assumptions for which options were granted: Three Months Ended March 31, 2018 2017 Risk-free interest rate — 1.97% - 2.40% Expected term — 6.1 - 9.6 yrs Expected dividends — 0% Volatility — 30% Restricted Stock Unit Awards The Company grants restricted stock units (RSU) to employees under the 2017 Plan. RSUs granted typically vest ratably over a four-year period and are converted into shares of the Company’s common stock upon vesting on a one-for-one basis subject to the employee’s continued service to the Company over that period. The fair value of RSUs is determined using the fair value of the Company’s common stock on the date of the grant, reduced by the discounted present value of dividends expected to be declared before the awards vest. Compensation expense is recognized on a straight-line basis over the requisite service period of each grant. Each RSU award granted from the 2017 Plan will reduce the number of shares available for issuance under the 2017 Plan by one share. For the three months ended March 31, 2018, unamortized compensation expense related to RSU was approximately $1.9 million, to be recognized over 2.5 years. For the year ended December 31, 2017, unamortized compensation expense related to RSU was approximately $0.4 million, to be recognized over 1.8 years. Activity under the Company’s RSU is set forth below : Number of Shares Balance—December 31, 2017 35,029 Granted 102,500 Released — Canceled — Balance—March 31, 2018 137,529 Employee Stock Purchase Plan Concurrent with the completion of the IPO in November 2017, the Company adopted the 2017 Employee Stock Purchase Plan, or ESPP. The ESPP authorizes the issuance of 647,494 shares of common stock outstanding under purchase rights granted to its employees. In addition, the shares reserved under the ESPP Plan will automatically increase on the first day of each calendar year, beginning on January 1, 2018 and ending on January 1, 2027, by the lesser of (i) an amount equal to 2% of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of the automatic increase, (ii) 1,000,000 shares of common stock, and (iii) a lesser number of shares determined by the board of directors prior to the date of such automatic increase. The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation, subject to any plan limitations. The ESPP generally provides for offering periods and purchase periods every six months, and at the end of each purchase period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock on the first trading day of the purchase period or on the last trading day of the offering period. Since the ESPP was established in November 2017, no shares were issued as of December 31, 2017. Shares expected to be issued under the ESPP were 226,000 for the offering period as of December 31, 2017. The calculated fair value of the shares under the ESPP was estimated using the Black-Scholes model with the following assumptions: risk-free interest rate of 1.31%, expected term of 0.5 year, expected dividends of 0% and volatility of 22%. For the three months ended March 31, 2018, unamortized compensation expense related to ESPP was approximately $0.1 million, to be recognized over approximately two months. For the year ended December 31, 2017, unamortized compensation expense related to ESPP was approximately $0.5 million, to be recognized over approximately five months. The Company uses the straight-line vesting attribution method to record stock-based compensation expense. Stock-based compensation expense recognized in the consolidated statements of operations and comprehensive loss for options, restricted stock units and ESPP was as follows (in thousands): Three Months Ended March 31, 2018 2017 Cost of revenue $ 25 $ 7 Research and development 573 132 Sales and marketing 111 27 General and administrative 269 76 Total $ 978 $ 242 No income tax benefit associated with stock-based compensation expense was recognized in the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2018 and 2017. |