Stockholders' Equity

3 Months Ended

Mar. 31, 2020

7. Stockholders’ Equity

Preferred Stock

As of March 31, 2020, 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

The following table presents information about warrants to purchase Common Stock issued and outstanding at March 31, 2020:


Year Issued	Warrants Outstanding	Exercise Price		Date of Expiration
2014	1,227	$	122.12	8/26/2021
2015	1,227	$	122.12	3/30/2022
2018	4,199,995	$	12.00	6/21/2023
2019	1,991,300	$	6.25	2/7/2024
Total	6,193,749
Weighted average exercise price		$	10.19
Weighted average life in years				3.43