10. Stockholders’ Equity

Shares issued

During the nine months ended September 30, 2020, the Company issued 691,820 shares of common stock upon vesting of Restricted Stock Units ("RSUs") granted by the Company.

During the nine months ended September 30, 2020, the Company issued 1,776,680 shares of common stock granted to Company Employees.

During the nine months ended September 30, 2020, the Company issued 325,242 shares of common stock upon vesting of RSUs granted to Board members.

During the nine months ended September 30, 2020, the Company issued 297,873 shares of common stock to a prior Company executive to fulfill obligations related to a separation agreement.

During the nine months ended September 30, 2020, the Company issued 23,078 shares of common stock to a consultant to fulfill obligations related to a consulting agreement.

During the nine months ended September 30, 2020, the Company issued 5,453 shares of common stock pursuant to the Officers and Directors Purchase Plan for proceeds of $5,750.

Stock-based compensation

The stock-based compensation expense was allocated as follows:

The following assumptions were used in the Black-Scholes-Merton pricing model to estimate the fair value of options granted during the periods presented. There were no options issued during the three and nine months ended September 30, 2020:

There were no stock option exercises during the three and nine months ended September 30, 2020 and September 30, 2019.

Restricted shares

In March 2020, the Company granted 830,000 restricted shares, all of which were subject to vesting, with a grant fair value of $280,000 to employees. The shares vest in three equal annual installments over a three-year period. No shares vested during the nine months ended September 30, 2020.

Restricted stock units

In March 2020, the Company granted 1,293,164 RSUs, all of which were subject to vesting, with a grant fair value of $440,000 to employees. The shares vest in six equal semi-annual installments over a three-year period. 355,018 shares vested during the nine months ended September 30, 2020.

In May 2020, the Company issued 1,970,475 RSUs, that were originally granted in March 2020, but were subject to approval of the amendment of the 2019 stock incentive plan at the Annual Shareholders Meeting. All of the RSUs were subject to vesting, with a grant fair value of $670,000 to employees. The shares vest in six equal semi-annual installments over a three-year period. 328,413 shares vested during the nine months ended September 30, 2020.

In May 2020, the Company granted 17,500 RSUs, all of which were subject to vesting, with a grant fair value of $16,000 to an employee. The shares vest in three equal installments over a three-year period. No shares vested during the nine months ended September 30, 2020.

In August 2020, the Company granted 367,500 RSUs, all of which were subject to vesting, with a grant fair value of $380,000 to employees. The shares vest upon the signing of a licensing agreement. No shares vested during the nine months ended September 30, 2020.