XML 41 R31.htm IDEA: XBRL DOCUMENT v3.8.0.1
Warrants (Tables)
9 Months Ended
Sep. 30, 2017
Schedule of warrants activity
Warrants outstanding and exercisable are summarized as follows:
 
 
 
Shares(1)
 
Weighted
Average
Exercise
Price
 
Range of
Exercise Prices
Outstanding at December 31, 2016
979,869

 
$
6.36

 
$2.20-$21.00
Exercised
(75,399
)
 
$
19.46

 
$13.25-$21.00
Expired

 
$

 
$—
Outstanding at September 30, 2017
904,470

 
$
5.27

 
$2.20-$21.00
Exercisable at September 30, 2017
904,470

 
$
5.27

 
$2.20-$21.00
 
 
(1) Outstanding and exercisable information includes 21,920 equity-classified warrants.

Black Scholes  
Schedule of Share Based Payment Award Warrants Valuation Assumptions
The assumptions used in the Black-Scholes option-pricing model to estimate the fair value of the warrant liability as of September 30, 2017 were as follows:
 
 
Expected volatility
88.7-101.0
Risk-free interest rate
1.47%-1.80%
Dividend yield
Expected life in years
2.0-4.2

Monte Carlo Simulation Model  
Schedule of Share Based Payment Award Warrants Valuation Assumptions
The assumptions used in the Monte Carlo simulation model to estimate the fair value of the warrant liability as of September 30, 2017 were as follows:
 
 
Expected volatility
62.0-89.7
Risk-free interest rate
1.26%-1.49%
Dividend yield
Expected life in years
0.8-2.1