11. Equity Incentive Plans

Restricted Stock Awards

During the nine months ended September 30, 2021 and 2020, the Company granted restricted stock awards (“RSA”) in lieu of cash payment for services performed. The estimated fair value of the RSAs was based on the market value of the Company’s common shares on the date of grant. During the nine months ended September 30, 2021 and 2020, the Company granted fully vested RSAs of 301,880 and 400,841, respectively, with a fair value of $1.4 million and $771,000, respectively.

Share-Based Compensation Expense

The Company recorded the following compensation expense related to its share-based compensation awards (in thousands):

As of September 30, 2021, there was $53,000 unrecognized compensation expense related to unvested equity-based compensation awards, and is expected to be recognized over a weighted average period of three months.

10.    Equity Incentive Plans

As of December 31, 2020, a total of 1,255,860 common shares are authorized for issuance with respect to awards granted under the 2015 Plan (not including shares subject to terminated awards under our Second Amended and Restated Stock Option Plan that become available for issuance under the 2015 Plan). In addition, the share limit will automatically increase on the first trading day in January of each calendar year during the term of the 2015 Plan by an amount equal to the lesser of (i) 10% of the total number of common shares issued and outstanding on December 31 of the immediately preceding calendar year, or (ii) such number of common shares as may be established by the Board. The 2015 Plan authorizes the board of directors to grant stock and options awards to directors, employees and consultants. As of December 31, 2020, the Company had approximately 51,500 share-based awards available for future grant.

The Company’s Employee Stock Purchase Plan (“ESPP”) authorizes the purchase of up to 37,500 common shares by employees under the plan. As of December 31, 2020 and 2019, there were no offering periods available to employees.

Stock Options

The options granted in 2020 were issued to non-employees for future services performed. The fair value of each option was estimated on the date of grant using the Black-Scholes option pricing model, using expected volatility of 125%, risk-free interest rate of .195% and expected term of 18 months. The expected volatility was based on the Company’s historical share price. The risk-free interest rate is determined based upon a constant maturity U.S. Treasury security with a contractual life approximating the expected term of the option. The expected term of options granted is based on term of the award. Option awards can be granted for a maximum term of up to ten years.

Option activity is summarized below:

Restricted Stock Units

The following table summarizes information about RSU activity:

The estimated fair value of RSUs was based on the market value of the Company’s common shares on the date of grant. RSUs typically vest over a three-year period from the original date of grant. The total grant date fair value of RSUs vested during the years ended December 31, 2020 and 2019 was approximately $0.1 million and $1.3 million, respectively. The fair value of RSUs vested during the years ended December 31, 2020 and 2019 was approximately $17,000 and $0.2 million, respectively.

Outside of 2015 Equity Incentive Plan

On March 26, 2019, the Board of Directors of the Company approved and granted 100,000 RSUs outside of the 2015 Plan to an employee. The RSUs have an estimated fair value of $2.51 per unit and fully vested in 2019.

Restricted Stock Awards

During 2020 and 2019, the Company granted restricted stock awards (“RSA”) to certain employees, directors and consultants in lieu of cash payment for services performed. The estimated fair value of the RSAs was based on the market value of the Company’s common shares on the date of grant. The RSAs were fully vested on the date of grant. The fair value of the RSAs vested during the years ended December 31, 2020 and 2019 was approximately $0.8 million and $0.2 million, respectively.

The following table summarizes information about RSA activity:

Share-Based Compensation Expense

The Company recorded the following compensation expense related to its share-based compensation awards (in thousands):

As of December 31, 2020, there was no unrecognized compensation expense related to unvested equity-based compensation awards.