PRSS 2017 Annual Report

60 6. Stockholders’ Equity Stock repurchase program InApril 2016, our Board of Directors approved the extension of our existing stock repurchase program that authorized the purchase of up to 20% of the outstanding shares of our common stock or an aggregate of 3.5 million shares of our common stock. Under the stock repurchase program, any stock repurchase could be made through open market and privately negotiated transactions, or as otherwise determined by management, at times and in such amounts as management deemed appropriate and could be made pursuant to one or more Rule 10b5-1 trading plans adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"). The timing and amount of stock repurchased under the program depended on a variety of factors including stock price, market conditions, corporate and regulatory requirements (including applicable securities laws and regulations and the rules of the NASDAQ Stock Market), any additional constraints related to material inside information the Company may have possessed and capital availability. In February 2017, our Board of Directors terminated the stock repurchase program. During 2017, we repurchased 18,861 shares of our common stock at an average cost of $3.10 per share for a total cost of $0.1 million. During 2016, we repurchased 315,503 shares of our common stock at an average cost of $3.22 per share for a total cost of $1.0 million Stock option plan The Company adopted stock option plans in 1999, 2004 and 2012 under which 4,534,239 options have been authorized but not issued as of December 31, 2017. The total remaining available to be granted as of December 31, 2017 is 1,524,304 shares. The plans are administered by the Board of Directors, which identifies optionees and determines the terms of options granted, including exercise price, number of shares subject to the option and exercisability thereof, except in the case of options granted to officers, directors and consultants under the 1999 Plan which options shall become exercisable at a rate of no less than 20% per year. The 1999 Plan provides for incentive stock options and stock appreciation rights to be issued to employees of the Company and non-statutory stock options, stock bonuses, and rights to purchase restricted stock to be issued to employees, directors, and consultants of the Company. The 2004 Plan provides for incentive stock options to be issued to employees of the Company and nonqualified stock options to be issued to employees, consultants, and outside directors of the Company. The 2012 Stock Plan provides for the granting of stock options, restricted stock, stock units and stock appreciation rights. Exercise prices for incentive stock options shall be no less than 100% of the fair market value of the common stock on the grant date. Exercise prices for non-statutory and nonqualified stock options may not be less than 85% of the fair market value of the common stock on the date of grant and are determined by the Board of Directors. Stock option awards generally vest with respect to 25% of the shares one year after the options' vesting commencement date, and the remainder ratably on a monthly basis over the following three years. Employee Stock Purchase Plan In August 2011, the Company’s Board of Directors approved the reservation for future issuance under the Company’s Employee Stock Purchase Plan, or the ESPP, of a total of 250,000 shares of common stock. The ESPP became effective immediately prior to the completion of the IPO. The price of stock purchased under the ESPP shall not be lower than 85% of the fair market value per share of the Company’s common stock on either the last trading day preceding the applicable offering period or on the last day of the purchase period, whichever is less. There have been no purchases under the ESPP in 2017 or 2016.