Stockholders' Equity	3 Months Ended
Mar. 31, 2019
Stockholders' Equity
Stockholders' Equity	7. Stockholders’ Equity Preferred Stock As of March 31, 2019, 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. Common Stock Warrants February 2019 Warrants In the February 2019 Financing, the Company issued warrants to purchase 2,000,000 shares of common stock with an exercise price of $6.25 per share, which were immediately exercisable upon issuance and will expire five years from the date of issuance. The terms of the warrants include certain provisions related to fundamental transactions, a cashless exercise provision in the event registered shares are not available and do not include any mandatory redemption provisions. Therefore, the warrants have been classified in stockholders’ equity. Any changes to the fair value of the warrants will not be recognized so long as the warrants continue to be equity classified. As of March 31, 2019, 1,999,500 warrants related to the February 2019 Financing were outstanding with a remaining contractual life of 4.86 years. June 2018 Warrants On June 19, 2018, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc. relating to an underwritten public offering (the "June 2018 Financing") of 4,200,000 shares of the Company's common stock , par value $0.001 per share, and accompanying warrants to purchase up to 4,200,000 shares of common stock. The warrants were issued at an exercise price of $12.00 per share, and were immediately exercisable upon issuance expiring five years from the date of issuance. The terms of the warrants include certain provisions related to fundamental transactions, a cashless exercise provision in the event registered shares are not available and do not include any mandatory redemption provisions. Therefore, the warrants have been classified in stockholders’ equity. Any changes to the fair value of the warrants will not be recognized so long as the warrants continue to be equity classified. As of March 31, 2019, all warrants related to the June 2018 Financing were outstanding with a remaining contractual life of 4.23 years.

7. Stockholders’ Equity

Preferred Stock

As of March 31, 2019, 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.

Common Stock Warrants

February 2019 Warrants

In the February 2019 Financing, the Company issued warrants to purchase 2,000,000 shares of common stock with an exercise price of $6.25 per share, which were immediately exercisable upon issuance and will expire five years from the date of issuance.

The terms of the warrants include certain provisions related to fundamental transactions, a cashless exercise provision in the event registered shares are not available and do not include any mandatory redemption provisions. Therefore, the warrants have been classified in stockholders’ equity. Any changes to the fair value of the warrants will not be recognized so long as the warrants continue to be equity classified.

As of March 31, 2019, 1,999,500 warrants related to the February 2019 Financing were outstanding with a remaining contractual life of 4.86 years.

June 2018 Warrants

On June 19, 2018, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc. relating to an underwritten public offering (the "June 2018 Financing") of 4,200,000 shares of the Company's common stock , par value $0.001 per share, and accompanying warrants to purchase up to 4,200,000 shares of common stock. The warrants were issued at an exercise price of $12.00 per share, and were immediately exercisable upon issuance expiring five years from the date of issuance.

As of March 31, 2019, all warrants related to the June 2018 Financing were outstanding with a remaining contractual life of 4.23 years.