Preferred Stock	12 Months Ended
Dec. 31, 2017
Preferred Stock
Preferred Stock	11. Preferred Stock Convertible Preferred Stock In March, 2015, the Company issued 13,062,965 shares of Series B Preferred Stock at $0.9503 per share, and received net proceeds of $12.3 million. Prior to the IPO, the holders of the Company's convertible Preferred Stock had certain voting and dividend rights, as well as liquidation preferences and conversion privileges. All rights, preferences, and privileges associated with the convertible Preferred Stock were terminated at the time of the Company's IPO in conjunction with the conversion of all outstanding shares of convertible Preferred Stock into shares of Common Stock. Upon the closing of the Company's IPO on June 30, 2015, all outstanding shares of the Company's Preferred Stock were automatically converted into 9,029,549 shares of Common Stock. As of December 31, 2016, the Company had 5,000,000 shares of Preferred Stock authorized for issuance, $0.001 par value per share, with none issued or outstanding. Preferred Stock As of December 31, 2017, the Company had 5,000,000 shares of preferred stock authorized for issuance, $0.001 par value per share, with none issued or outstanding. Preferred stock may be issued from time to time in one or more series, each series to have such terms as stated or expressed in the resolutions providing for the issue of such series adopted by the board of directors of the Company. Preferred stock which may be redeemed, purchased or acquired by the Company may be reissued except as otherwise provided by law.

11. Preferred Stock

Convertible Preferred Stock

In March, 2015, the Company issued 13,062,965 shares of Series B Preferred Stock at $0.9503 per share, and received net proceeds of $12.3 million. Prior to the IPO, the holders of the Company's convertible Preferred Stock had certain voting and dividend rights, as well as liquidation preferences and conversion privileges. All rights, preferences, and privileges associated with the convertible Preferred Stock were terminated at the time of the Company's IPO in conjunction with the conversion of all outstanding shares of convertible Preferred Stock into shares of Common Stock. Upon the closing of the Company's IPO on June 30, 2015, all outstanding shares of the Company's Preferred Stock were automatically converted into 9,029,549 shares of Common Stock. As of December 31, 2016, the Company had 5,000,000 shares of Preferred Stock authorized for issuance, $0.001 par value per share, with none issued or outstanding.

Preferred Stock

As of December 31, 2017, the Company had 5,000,000 shares of preferred stock authorized for issuance, $0.001 par value per share, with none issued or outstanding. Preferred stock may be issued from time to time in one or more series, each series to have such terms as stated or expressed in the resolutions providing for the issue of such series adopted by the board of directors of the Company. Preferred stock which may be redeemed, purchased or acquired by the Company may be reissued except as otherwise provided by law.