DERIVATIVE WARRANT LIABILITY (Tables)

6 Months Ended

Jun. 30, 2017

Disclosure Text Block [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The underlying assumptions used in the binomial model to determine the fair value of the derivative warrant liability were:

	Three months ended
	June 30, 2017	March 31, 2017
Stock price on valuation date	$ 1.37 – 2.20	$  2.21 – 3.25
Risk-free interest rate	1.3 – 1.4 %	1.3 – 1.5 %
Expected dividend yield	--	--
Expected term (in years)	2.2 – 2.5	2.5 – 2.7
Expected volatility	131 – 134 %	146 – 153 %
Number of iterations	5	5

Derivative Instruments, Gain (Loss) [Table Text Block]

Changes in the derivative warrant liability were as follows:

December 31, 2016	$	23,120,000
Decrease in fair value		(8,159,000)
Reclassification to additional paid-in capital upon exercise of warrants		(7,301,000)
June 30, 2017	$	7,660,000