Stockholders' Equity

12 Months Ended

Dec. 31, 2015

Consolidated Statements of Stockholders' Equity

Stockholders' Equity

11. Stockholders' Equity

Preferred Stock

        The Company has authorized 5.0 million shares of preferred stock, par value $0.01 per share. The Company's certificate of incorporation provides that shares of preferred stock may be issued from time to time in one or more series. The Company's Board of Directors is authorized to fix the voting rights, if any, designations, powers, preferences, qualifications, limitations and restrictions thereof, applicable to the shares of each series.

        The Company has authorized Series A Junior Participating Cumulative Preferred Stock, par value $.01 per share. As of December 31, 2015 and 2014, there were no shares of Series A Junior Participating Cumulative Preferred Stock issued and outstanding.

Common Stock and Warrants

        The Company has one class of common stock, par value $0.01 per share. Each share of the Company's common stock is entitled to one vote on all matters submitted to stockholders. There were 180,087,491 and 173,266,416 shares of common stock outstanding as of December 31, 2015 and 2014, respectively.

        During 2014, the Company completed a series of underwritten public offerings, aggregating to issuances of 36,502,440 shares of common stock. The share prices ranged from $5.50 to $5.74 with respect to 26,502,440 of the shares. One of the underwritten public offerings included accompanying warrants to purchase 4,000,000 shares of common stock. The shares and the warrants were sold together in a fixed combination, with each combination consisting of one share of common stock and 0.40 of a warrant to purchase one share of common stock, at a price of $3.00 per fixed combination for 10,000,000 shares. The total net proceeds to the Company from the 2014 public offerings were $165.7 million, of which $11.8 million in value was ascribed to the warrants issued in the January 2014 public offering. The warrants have an exercise price of $4.00 per share, were immediately exercisable and will expire on January 15, 2019.

        During 2013, the Company completed a series of underwritten public offerings, aggregating to issuances of 43,101,800 shares of common stock. The share price was $0.54 with respect to 21,390,000 of the shares. One of the underwritten public offerings included accompanying warrants to purchase 21,711,800 shares of common stock. The shares and the warrants were sold together in a fixed combination, with each combination consisting of one share of common stock and one warrant to purchase one share of common stock, at a prices ranging from $0.15 to $0.18 per fixed combination. The total net proceeds to the Company from the 2013 public offerings were $12.9 million, of which $2.5 million in value was ascribed to the warrants issued in the February 2013 public offering. The warrants have exercise prices ranging from $0.15 to $0.18 per share, are exercisable and will expire in February 2018.

        During the years ended December 31, 2015, 2014 and 2013, 26,882, 23,918,429 and 22,494,987 warrants were exercised, respectively, resulting in the issuance of shares of common stock of 26,882, 23,832,038 and 22,494,987, respectively, and gross proceeds of $25 thousand, $18.3 million and $6.1 million, respectively, and increase of paid-in capital and reduction of the warrant liability by $22 thousand, $83.4 million and $11.2 million, respectively. At December 31, 2015 and 2014, the Company has 4,192,567 and 4,219,449 warrants outstanding and exercisable. The warrants are measured at fair value and classified as a liability on the consolidated balance sheets.