Stock-Based Compensation | The following table summarizes the activity for all stock options outstanding for the three months ended March 31: 2020 2019 Shares Weighted Average Exercise Price Shares Weighted Average Exercise Price Options outstanding at beginning of year 585,215 $ 14.37 478,503 $ 9.73 Granted 57,500 10.17 250 22.22 Exercised - - (22,733 ) 7.69 Forfeited (11,826 ) 10.60 (67,055 ) 9.37 Balance at March 31 630,889 $ 14.06 388,965 $ 9.91 Options exercisable at March 31: 274,267 $ 9.65 253,719 $ 7.09 Weighted Average Grant Date Fair Value for options granted during the period: $ 6.59 $ 15.53 The following table summarizes additional information about stock options outstanding and exercisable at March 31, 2020: Options Outstanding Options Exercisable Options Outstanding Weighted Average Remaining Contractual Life Weighted Average Exercise Price Aggregate Intrinsic Value Options Exercisable Weighted Average Exercise Price Aggregate Intrinsic Value 630,889 8.07 $ 14.06 $ 233,614 274,267 $ 9.65 $ 233,614 The Company recognized stock-based compensation expense for stock options of $450,664 and $162,829 for the three months ended March 31, 2020 and 2019, respectively. The Black-Scholes option-pricing model was used to estimate the fair value of equity-based awards with the following weighted-average assumptions for the three months ended March 31: 2020 2019 Risk-free interest rate 1.35% - 1.66 % 2.47 % Expected volatility 73.3 % 80.0 % Expected life (years) 5.5 to 6.1 6.05 Expected dividend yield 0 % 0 % The inputs for the Black-Scholes valuation model require management’s significant assumptions. Prior to the Company’s initial public offering, the price per share of common stock was determined by the Company’s board based on recent prices of common stock sold in private offerings. Subsequent to the initial public offering, the price per share of common stock is determined by using the closing market price on the Nasdaq Capital Market on the grant date. The risk-free interest rates are based on the rate for U.S. Treasury securities at the date of grant with maturity dates approximately equal to the expected life at the grant date. The expected life is based on the simplified method in accordance with the SEC Staff Accounting Bulletin Nos. 107 and 110. The expected volatility is estimated based on historical volatility information of peer companies that are publicly available in combination with the Company’s calculated volatility since being publicly traded. All assumptions used to calculate the grant date fair value of non-employee options are generally consistent with the assumptions used for options granted to employees. In the event the Company terminates any of its consulting agreements, the unvested options issued in connection with the agreements would also be cancelled. Unvested non-employee options were marked-to-market through April 1, 2018, the date that the Company adopted ASU No. 2018-07, Improvements to Non-employee Share-Based Payment Accounting. No restricted stock awards were granted during the three months ended March 31, 2020 and 2019. The Company had 0 and 2,571 shares of restricted stock outstanding as of March 31, 2020 and 2019, respectively, and 0 shares of restricted stock vested during the three months ended March 31, 2020 and 2019. The Company recognized stock-based compensation expense for restricted stock of $0 and $12,786 for the three months ended March 31, 2020 and 2019, respectively. The Company initially reserved a maximum of 750,000 shares of common stock for issuance under the 2017 Stock Incentive Plan (the “2017 Plan”). The number of shares reserved for issuance was automatically increased by 102,540 shares on January 1, 2020 and will increase automatically on January 1 of each of 2021 through 2027 by the number of shares equal to 1.0% of the aggregate number of outstanding shares of Company common stock as of the immediately preceding December 31. However, the board may reduce the amount of the increase in any particular year. The total remaining shares available for grant under the Company’s 2017 Plan as of March 31, 2020 is 433,668. Total unrecognized compensation cost related to stock options and restricted stock is estimated to be recognized as follows: 2020 $ 910,860 2021 1,008,493 2022 870,596 2023 530,290 2024 91,505 Total estimated compensation cost to be recognized $ 3,411,744 The Company recognized stock-based compensation expense related to its employee stock purchase plan of $13,985 and $9,030 for the three months ended March 31, 2020 and 2019, respectively. The Company initially reserved a total of 100,000 shares for issuance under the employee stock purchase plan. The number of shares reserved for issuance was automatically increased by 51,270 shares on January 1, 2020 and will increase automatically on each subsequent January 1 by the number of shares equal to 0.5% of the total outstanding number of shares of Company common stock as of the immediately preceding December 31. However, the board may reduce the amount of the increase in any particular year. The total remaining shares available for issuance under the employee stock purchase plan as of March 31, 2020 is 124,634. The Company recognized total stock-based compensation expense as follows for the three months ended March 31: Three Months Ended March 31, 2020 2019 Stock-based compensation expense in operating expenses: Research and development $ 293,116 $ 100,257 General and administrative 171,533 84,388 Total $ 464,649 $ 184,645 |