10. Stock-Based Compensation

Equity Incentive Plans – The Company’s 2013 Equity Compensation Plan (the “2013 Plan”) was adopted for the purpose of providing equity incentives to employees, officers, directors and consultants including options, restricted stock, restricted stock units, stock appreciation rights, other equity awards, annual incentive awards and dividend equivalents. The Company amended the 2013 Plan to increase the number of authorized shares of common stock under the Plan from 225,000 shares to 615,000 shares, which the Company’s stockholders approved on June 26, 2017. The Company further amended the 2013 Plan to increase the number of authorized shares of common stock under the Plan by 300,000 shares, which the Company’s stockholders approved and ratified on November 8, 2018. The Company is now authorized to issue 915,000 shares under the amended 2013 Plan.

Stock Options

The following tables summarize the Company’s stock option activity for the six months ended June 30, 2019, and 2018:

On March 11, 2019, the Company granted 30,000 stock options to CFO Adam He, in connection with his employment agreement. These options had an aggregate fair value of $54,000, using the Black-Scholes option-pricing model with the following assumptions:

The March 11, 2019 options granted are exercisable at an exercise price of $2.23 over a ten-year term and vest over two years, with one-third vested upon grant.

The Company recorded non-cash compensation expense, which is included in general and administrative expenses in the accompanying condensed consolidated statement of operations, of approximately $18,000 and $298,000 for the three months ended June 30, 2019 and 2018, respectively, and approximately $23,000 and $387,000 for the six months ended June 30, 2019 and 2018, respectively related to stock option grants.

Total unrecognized compensation expense related to unvested stock options at June 30, 2019 amounted to approximately $72,000 and is expected to be recognized over a remaining weighted average period of 1.1 years.

Warrants

As of June 30, 2019, there were 153,907 warrants outstanding and exercisable, with a weighted average exercise price of $27.37 per share. The weighted average remaining contractual life of the warrants at June 30, 2019 and December 31, 2018 was 1.8 and 2.6 years, respectively, and the aggregate intrinsic value was 0.

The Company did not grant any warrants to purchase shares of common stock during the six months ended June 30, 2019.

No compensation cost was recognized for the three and six months ended June 30, 2019, and 2018 pertaining to warrants.

Restricted Stock and Restricted Stock Units

During the first six months of 2019, the Company granted 46,402 restricted stock units (“RSUs”) to certain Board members and 1,166 RSUs to CFO Adam He. The RSUs granted to Board members vest one year after they were awarded (with the ex, subject to continued service on the vesting date), and the RSUs granted to CFO Adam He vested immediately. The RSUs have no voting or dividend rights. The fair value of the common stock on the dates of grant were $3.09 and $3.32 per share, based upon the closing market price on the grant dates. The aggregate grant date fair value of the combined awards amounted to $156,000.

A summary of the restricted stock award activity for the six months ended June 30, 2019, and 2018 is as follows:

The Company recorded non-cash compensation expenses of approximately $73,000 and $49,000 for the three months ended June 30, 2019 and 2018, respectively, and approximately $75,000 and $79,000 for the six months ended June 30, 2019 and 2018, respectively, related to restricted stock grants.

Total unrecognized compensation expense related to unvested restricted stock and unvested restricted stock units at June 30, 2019 amounts to approximately $140,000 and is expected to be recognized over a weighted average period of 0.4 year.