Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2020

Stockholders' Equity

Schedule of warrants outstanding

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