Note 12 - Warrants

6 Months Ended

Jun. 30, 2017

Notes to Financial Statements

Warrants [Text Block]

Note 1 2 . Warrants

Common Stock Warrants

Following is a summary of all warrant activity for the

six

months ended

June 30, 2017: 

Warrants	Number of Warrants Issued			Weighted Average Exercise Price
Warrants outstanding at December 31, 2016		1,487,958		$	9.39
Warrants issued during the six months ended June 30, 2017 (see Note 9)		1,363,503			2.80
Warrants exercised during the six months ended June 30, 2017 (see Note 9)		(2,251,606	)		2.25
Warrants outstanding at June 30, 2017		599,855		$	21.22
Aggregate intrinsic value of outstanding warrants at June 30, 2017	$	─
Weighted average remaining contractual terms at June 30, 2017 (in years)		4.26