7. Common Stock

Common Stock

Pursuant to the Company’s Third Amended and Restated Certificate of Incorporation (the amended and restated certificate of incorporation) filed in October 2019, the Company is authorized to issue 143,590,481 shares of voting common stock and 6,409,519 shares of non-voting common stock. Holders of voting common stock shall have the exclusive right to vote for the election of directors of the Company and on all other matters requiring stockholder action. Each share of the Company’s non-voting common stock may be converted at any time into one share of common stock at the option of its holder by providing 61 days written notice to the Company, subject to certain limitations, as described in the amended and restated certificate of incorporation.

2018 Stock Option and Grant Plan

In September 2018, the Company adopted the 2018 Stock Option and Grant Plan (the 2018 Plan), which provided for the Company to sell or issue common stock, or other stock-based awards, to employees, members of the board of directors and consultants of the Company. The Company generally granted stock-based awards with service conditions only (service-based awards), although there was one grant with performance conditions. As of March 31, 2021, there were no unvested options with performance conditions. Stock options granted under the 2018 Plan generally vest over three to four years. There were 1,959,411 options granted under the 2018 Plan prior to the Company’s IPO in October 2019. No further grants may be made under the 2018 Plan subsequent to the IPO.

2019 Stock Option and Incentive Plan

 The 2019 Stock Option and Incentive Plan (2019 Plan) was approved by the Company’s board of directors on October 14, 2019, and became effective on October 23, 2019. The 2019 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights to the Company’s officers, employees, directors and consultants. The number of shares initially reserved for issuance under the 2019 Plan was 2,342,288, and such number of shares will be increased each January 1 thereafter by 4% of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or such lesser number of shares determined by the Company’s board of directors or compensation committee of the board of directors. On January 1, 2021, the total number of shares under the 2019 Plan was increased by 962,511 shares. As of March 31, 2021, there were 2,173,804 shares remaining available for issuance.

A summary of stock option activity is presented below:

The aggregate intrinsic value of options granted is calculated as the difference between the exercise price of the options and the estimated fair value of the Company’s common stock. The weighted average grant-date fair value of stock options granted during the three months ended March 31, 2021 and 2020 was $7.93 and $9.44, respectively.

The fair value of each award is estimated using Black-Scholes based on the following assumptions:

Black-Scholes requires the use of subjective assumptions which determine the fair value of stock-based awards. These assumptions include:

Fair value of common stock—Prior to the Company’s IPO in October 2019, the fair value of the Company’s common stock underlying stock-based awards was estimated on each grant date by the Company’s board of directors. In order to determine the fair value of the Company’s common stock underlying stock-based awards, the Company’s board of directors considered, among other things, a valuation of the Company’s common stock prepared by an unrelated third-party valuation firm in accordance with the guidance provided by the American Institute of Certified Public Accountants Practice Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation.

Expected term—The expected term represents the period that stock-based awards are expected to be outstanding. The expected term for option grants is determined using the simplified method, which is the midpoint between the vesting period and the contractual term of the option.

Expected volatility—As a privately held company prior to the Company’s IPO in October 2019, the Company has limited trading history for its common stock and, as such, the expected volatility is estimated based on the average volatility for comparable publicly traded biotechnology companies over a period equal to the expected term of the stock-based awards. The comparable companies were chosen based on their similar size, stage in the life cycle or area of specialty. The Company will continue to apply this process until a sufficient amount of historical information regarding the volatility of its own stock price becomes available.

Risk-free interest rate—The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of a stock-based award.

Expected dividend—The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero.

Stock-based Compensation

The Company has recorded stock-based compensation in the accompanying statements of operations as follows:

As of March 31, 2021, there was $17,450 of unrecognized compensation cost related to unvested option awards, which is expected to be recognized over a weighted-average period of 3.2 years.

2019 Employee Stock Purchase Plan

The 2019 Employee Stock Purchase Plan (2019 ESPP) was approved by the Company’s board of directors on October 14, 2019, and became effective on October 23, 2019. A total of 234,229 shares of common stock were initially reserved for issuance under the 2019 ESPP, and such number of shares will be increased each January 1 thereafter through January 1, 2029 by the least of (i) 234,229 shares of common stock, (ii) 1% of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or (iii) such lesser number of shares determined by the 2019 ESPP’s administrator. On January 1, 2021, the total number of shares under the 2019 ESPP was increased by 234,229 shares.

Employee contributions are made through payroll deductions of up to 15% of eligible compensation over the offering period. A participant may not accrue rights to purchase more than $25 worth of the Company’s common stock for each calendar year in which such right is outstanding. At the end of each offering period, shares of the Company’s common stock may be purchased at 85% of the lesser of the Company’s common stock on (i) the first trading day of the relevant offering period and (ii) the last trading day of the relevant offering period. The first offering period commenced on July 1, 2020 and ended on November 30, 2020. Thereafter, offerings will be six months in duration and will commence on each December 1 and June 1.