(8)

Warrants

(a) Lender Warrant

On May 23, 2005, the Company entered into a Senior Loan and Security Agreement, or Hercules Debt, with Hercules. On September 27, 2007, the Company repaid the loan to Hercules. In connection with the Hercules Debt financing, the Company granted Hercules a warrant, or Lender Warrant, to purchase 423,529 shares of Series C Redeemable Preferred Stock at a purchase price of $4.25 per share. Upon the automatic conversion of the Company’s preferred stock into common stock in connection with the closing of the Company’s IPO on May 15, 2012, the Lender Warrant became exercisable for 211,764 shares of common stock at a purchase price of $8.50 per share. In January 2013, the Lender Warrant was net exercised, resulting in 117,166 common shares being issued at an exercise price of $8.50 per share. The cashless net exercise resulted in no cash being received by the Company as the shares withheld were applied to settle the exercise price owed by the exercising stockholder.

(b) Investor Warrants

On December 28, 2009, in connection with the Company entering into certain convertible note agreements with several existing Preferred Stockholders, the Company granted to the instrument holders warrants, or Investor Warrants, to purchase Series E Preferred Stock (later amended to Series E-1 Preferred Stock). Upon the automatic conversion of the Company’s preferred stock into common stock in connection with the closing of the Company’s IPO on May 15, 2012, the Investor Warrants became exercisable for 4,366,803 shares of common stock. In November 2012, the Company issued common shares, net of shares withheld, in connection with the exercise of the Investor Warrants by certain stockholders. The common shares were issued at an exercise price of $4.58 per share. Following this exercise, stockholders held Investor Warrants that were exercisable for 472,736 common shares; these remaining Investor Warrants were net exercised in January 2013, resulting in 350,705 common shares being issued at an exercise price of $4.58 per share. The cashless net exercise resulted in no cash being received by the Company as the shares withheld were applied to settle the exercise price owed by the exercising stockholder.