Note 6 – Stock-based compensation

The Company recorded approximately $120 and $332 of stock-based compensation related to employee stock options for the three and nine months ended September 30, 2018 and $142 and $409 for the three and nine months ended September 30, 2017, respectively. As of September 30, 2018, there was $2,163 of unrecognized compensation cost related to outstanding options that is expected to be recognized as a component of the Company’s operating expenses over a weighted average period of 2.4 years.

As of September 30, 2018, an aggregate of 2,239,000 shares of common stock were reserved for issuance under the Company’s 2007 Equity Incentive Plan (the “Prior Plan”) and the Company’s 2015 Equity Incentive Plan (the “2015 Plan” and together with the Prior Plan, the “Plans”), including 1,351,000 shares subject to outstanding stock options granted under the Plans and 888,000 shares available for future grants under the 2015 Plan. The administrator of the Plans determines the times when an option may become exercisable at the time of grant. Vesting periods of options granted to date have not exceeded five years. The options generally will expire, unless previously exercised, no later than ten years from the grant date. The Company is using unissued shares for all shares issued for options and restricted share awards.

The following schedule presents activity in the Company’s outstanding stock options for the nine months ended September 30, 2018 (in thousands, except per share amounts):

As of September 30, 2018, options to purchase 1,351,000 shares of common stock, with no aggregate intrinsic value, were outstanding that were fully vested or expected to vest with a weighted average remaining contractual term of 7.6 years. The aggregate intrinsic value of outstanding and exercisable options at September 30, 2018 was calculated based on the closing price of the Company’s common stock as reported on the Nasdaq Capital Markets on September 30, 2018 of $2.50 per share less the exercise price of the options. The aggregate intrinsic value is calculated based on the positive difference between the closing fair market value of the Company’s common stock and the exercise price of the underlying options.