Preferred Stock and Stockholders’ Equity

Preferred Stock

Under the Company’s amended and restated certificate of incorporation, as of December 31, 2015 and 2014, the Company is authorized to issue 10,000,000 shares of preferred stock with a $0.001 par value. As of December 31, 2015 and 2014, there were no shares of preferred stock issued or outstanding.

Common Stock

Under the Company’s amended and restated certificate of incorporation, as of December 31, 2015 and 2014, the Company was authorized to issue 50,000,000 shares of common stock with a $0.001 par value. Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends whenever funds are legally available, when declared by the board of directors, subject to the prior rights of holders of convertible preferred stock.

Common stock reserved for future issuance is as follows (in thousands):



	December 31,
	2015	2014
Stock options and restricted stock units outstanding	2,714	2,114
Warrants to purchase common stock	1,975	2,029
Shares authorized for future issuance under equity and purchase plans	678	603
	5,367	4,746

Common Stock Warrants

In December 2014, and in connection with entering into the Loan and Security Agreement (see Note 10), the Company issued warrants to Oxford and SVB exercisable into an aggregate of 63,559 shares of common stock. The warrants are exercisable at $9.44 per share of common stock and have a term of 10 years. During the year ended December 31, 2015, warrants to purchase 31,779 shares of common stock were exercised in a cashless exercise whereby 16,719 shares were issued and 15,060 shares withheld to satisfy the exercise price of the warrants. The value of the warrants of approximately $558,000 was recorded as debt discount and additional paid in capital in the consolidated balance sheet as of December 31, 2014.

In July 2012, in connection with a public offering of common stock and warrants, the Company sold warrants to purchase 1,973,025 shares of common stock (including over-allotment purchase). The warrants are exercisable at an exercise price of $20.00 per share and will expire on July 27, 2017, which is five years from the date of issuance. As the warrants contain a cash settlement feature upon the occurrence of certain events that may be outside of the Company's control, the warrants are recorded as a current liability and are marked to market at each reporting date (see Note 2). None of these warrants were exercised during the year ended December 31, 2015. During the year ended December 31, 2014, warrants to purchase 58,156 shares of common stock were exercised. The fair value of the warrants outstanding was approximately $6,069,000 and $4,978,000 as of December 31, 2015 and 2014, respectively.

In July 2011, upon the closing of and in connection with the Healthcare Royalty Financing Agreement (see Note 10), the Company issued a warrant to Healthcare Royalty exercisable into 28,125 shares of common stock. The warrant is exercisable at $72.00 per share of common stock and has a term of 10 years. As the warrant contains covenants where compliance with such covenants may be outside of the Company’s control, the warrant was recorded as a current liability and is marked to market at each reporting date (see Note 2). The fair value of the warrant was approximately $127,000 and $115,000 as of December 31, 2015 and 2014, respectively.

In June 2011, and in connection with entering into an amendment to the second amended and restated loan and security agreement with Oxford and CIT Healthcare LLC (the Oxford Agreement), the Company issued warrants to Oxford and SVB exercisable into an aggregate of 3,306 shares of common stock. The warrants are exercisable at $30.24 per share of common stock and have a term of 7 years. The value of the warrants of approximately $76,000 was recorded as debt discount and additional paid in capital in the consolidated balance sheet as of December 31, 2011.