On June 30, 2020, the Company issued 1,718 shares of common stock, in aggregate, for debt conversions of $1,000 aggregate principal amount of the 8% Notes, related shares of Series C Preferred Stock, and of $4,185 aggregate principal amount of the 10% Note. The Company also issued 93 shares of common stock for Series C Preferred Stock discussed above (Note 10).

Restricted Stock

The Company did not grant restricted stock during the three-month periods ended December 31, 2020 and 2019. Stock-based compensation expense attributable to restricted stock was $176 and $757 during the three-month periods ended December 31, 2020 and 2019, respectively. As of December 31, 2020, there was approximately $641 of unrecognized compensation expense related to restricted stock outstanding.

Warrants

No warrants were granted or exercised during the three-month periods ended December 31, 2020 and 2019.

Stock Options

As of December 31, 2020, there were stock options outstanding under the Company’s Amended and Restated 2013 Incentive Stock Plan. During fiscal 2020, 2013 Incentive Stock Plan was amended to increase available balance by 1,000 stock options. Compensation Committee of the Board of Directors authorized to grant either incentive or non-statutory stock options to employees. Vesting periods are established by the Compensation Committee at the time of grant. All stock options outstanding as of December 31, 2020 and September 30, 2020 were non-statutory stock options, had exercise prices equal to the market price on the date of grant, and had expiration dates ten years from the date of grant.

Stock-based compensation expense attributable to stock options and warrants was $135 and $(160) for the three-month periods ended December 31, 2020 and 2019, respectively. As of December 31, 2020, there was approximately $534 of unrecognized compensation expense related to unvested stock options outstanding, and the weighted average vesting period for those options was 3.96 years.

On June 30, 2020, the Company issued 1,718 shares of common stock for debt conversion of $1,000 aggregate principal amount of the 8% Notes, related shares of Series C Preferred Stock and 10% Note. The Company also issued 93 shares of common stock for Series C Preferred Stock discussed above (Note 10).

During fiscal 2019 the Company issued 250 shares of common stock for the conversion of approximately 250 shares of Series B Convertible Preferred Stock (See Note 12).

Restricted Stock

The Company granted 450 and 400 shares of restricted common stock in fiscal 2020 and 2019, respectively. The restricted shares are to be earned over a three-year period and cliff vest at the end of the third year from the date of grant. Stock-based compensation expense attributable to restricted stock was $1,150 and $819 in fiscal 2020 and fiscal 2019, respectively. As of September 30, 2020, there was $818 of unrecognized compensation expense related to restricted stock outstanding. On November 23, 2019, 500 shares of restricted common stock held by the Company’s former president became fully vested upon his passing. These shares were issued during fiscal 2020.

A summary of restricted stock activity is presented as follows:

Warrants

No warrants were granted or exercised during fiscal 2020 or fiscal 2019.

A summary of warrant activity is presented as follows:

Stock Options

As of September 30, 2020, there were stock options outstanding under the Company’s Amended and Restated 2013 Incentive Stock Plan. During fiscal 2020, 2013 Incentive Stock Plan was amended to increase available balance by 1,000. The plan granted specified numbers of options to non-employee directors, and they authorized the Compensation Committee of the Board of Directors to grant either incentive or non-statutory stock options to employees. Vesting periods are established by the Compensation Committee at the time of grant. All stock options outstanding as of September 30, 2020 and September 30, 2019 were non-statutory stock options, had exercise prices equal to the market price on the date of grant, and had expiration dates ten years from the date of grant.

Stock-based compensation expense attributable to stock options and warrants was $409 and $1,367 in fiscal 2020 and fiscal 2019, respectively. As of September 30, 2020, there was approximately $652 of unrecognized compensation expense related to unvested stock options outstanding, and the weighted average vesting period for those options was 3.95 years.

The fair value of stock options granted was made using the Black-Scholes option pricing model and the following assumptions: