Note 7 - Stock-Based Compensation

a) Warrants

The following table summarizes the changes in warrants outstanding of the Company during the six-month period ended June 30, 2021:

Effective January 1, 2021, the Company granted warrants to purchase 125,000 shares of common stock to a Company employee for services to the Company. These warrants vest on January 1, 2022 (subject to continued employment through such date) and expire on January 1, 2027, with an exercise price of $3.95 per share. The Company has calculated the estimated fair market value of these warrants at $242,877, using the Black-Scholes model and the following assumptions: term 3.5 years, stock price $3.95, exercise price $3.80, 74.53% volatility, 0.50% risk free rate, and no forfeiture rate.

Effective February 1, 2021, the Company granted warrants to purchase 185,000 shares of common stock to a Company employee for services to the Company. These warrants vest on February 1, 2022 (subject to continued employment through such date) and expire on February 1, 2027, with an exercise price of $4.90 per share. The Company has calculated the estimated fair market value of these warrants at $459,352, using the Black-Scholes model and the following assumptions: term 3.5 years, stock price $4.90, exercise price $4.80, 75.03% volatility, 0.59% risk free rate, and no forfeiture rate.

Below is a table summarizing the warrants issued and outstanding as of June 30, 2021, which have an aggregate weighted average remaining contractual life of 4.46 years.

Stock-based compensation expense related to warrants of $337,823 and $41,587 was recorded in the six months ended June 30, 2021 and June 30, 2020, respectively. Total remaining unrecognized compensation cost related to non-vested warrants is $402,971 and is expected to be recognized over a period of 0.59 years. As of June 30, 2021, the total intrinsic value of warrants outstanding was $102,500.

b) Options

The following table summarizes the changes in options outstanding of the Company during the six-month period ended June 30, 2021:

Effective May 20, 2021, the Company granted stock options to purchase 40,000 shares of common stock to a Company employee in exchange for services provided to the Company. These options vest on May 20, 2022 and expire five years after the vesting date, with an exercise price of $3.60 per share. The Company has calculated the estimated fair market value of these options at $73,641, using the Black-Scholes model and the following assumptions: term 3.5 years, stock price $3.50, exercise price $3.60, 76.16% volatility, 0.58% risk free rate, and no forfeiture rate.

Below is a table summarizing the options issued and outstanding as of June 30, 2021, all of which were issued pursuant to the 2011 Equity Incentive Plan (for option issuances prior to 2016) or the 2015 Stock Incentive Plan (for option issuances commencing in 2016) and which have an aggregate weighted average remaining contractual life of 2.54 years. As of June 30, 2021, an aggregate of 6,000,000 shares of common stock were authorized for issuance under the 2015 Stock Incentive Plan, of which 1,968,852 shares of common stock remained available for future issuance thereunder.

Stock-based compensation expense related to stock options of $418,292 and $482,103 was recorded in the six months ended June 30, 2021 and June 30, 2020, respectively. Total remaining unrecognized compensation cost related to non-vested stock options is $72,095 and is expected to be recognized over a period of 0.89 years. As of June 30, 2021, the total intrinsic value of stock options outstanding was $25,400.

c) Restricted Stock Units (RSUs)

Below is a table summarizing the RSUs issued and outstanding as of June 30, 2021, all of which were issued pursuant to the 2015 Stock Incentive Plan.

Effective January 1, 2021, the Company granted RSUs of 5,000 shares of common stock to a Company employee in exchange for services provided to the Company. These RSUs vested immediately, on January 1, 2021 and resulted in the issuance of 3,000 shares (the remaining 2,000 shares were withheld for taxes and returned as authorized shares under the 2015 Stock Incentive Plan) and total compensation expense of $19,450.

Effective March 25, 2021, the Company granted aggregate RSUs of 30,000 shares of common stock to two non-executive directors in exchange for services provided to the Company. These RSUs vest over two years, with 50% vesting on each of March 25, 2022 and March 25, 2023 and will result in total compensation expense of $107,700.

On March 25, 2021, 15,000 RSUs previously granted to a non-executive director were cancelled and returned as authorized shares under the 2015 Stock Incentive Plan upon the resignation of such director prior to vesting.

On April 13, 2021, 26,250 RSUs vested and resulted in the issuance of 21,712 shares (the remaining 4,538 shares were withheld for taxes and returned as authorized shares under the 2015 Stock Incentive Plan).

Effective May 1, 2021, the Company granted RSUs of 150,000 shares of common stock to an employee in exchange for services provided to the Company. These RSUs vest over three years with 50,000 units vesting on each of May 1, 2022, May 1, 2023 and May 1, 2024, respectively, and will result in total compensation expense of $496,500

Below is a table summarizing the RSUs issued and outstanding as of June 30, 2021 and which have an aggregate weighted average remaining contractual life of 1.62 years.

Stock-based compensation expense related to RSUs of $136,971 and $29,619 was recorded in the six months ended June 30, 2021 and June 30, 2020, respectively. Total remaining unrecognized compensation cost related to non-vested RSUs is $568,243. As of June 30, 2021, the total intrinsic value of the RSUs outstanding was $nil.