STOCKHOLDERS' EQUITY (Tables)

12 Months Ended

Dec. 31, 2016

Stock-based compensation expense recognized under ASC 718 was as follows:

	December 31,
	2016		2015		2014
Research and development	$	-	$	-	$	-
General and administrative		133,904		105,782		21,416
Total stock-based compensation expense	$	133,904	$	105,782	$	21,416

The following table presents the assumptions used to estimate the fair values of the stock options granted in the periods presented:

The summary of the stock options activity is as follows for year ended:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term		Aggregate Intrinsic Value
Outstanding at January 1, 2015		759,958		$	11.04		3.12	$	23,483,235
Grants		30,000			37.64		10.00		-
Exercised		(227,958	)		12.39		-		9,251,027
Forfeitures or expirations		-			-		-		-
Outstanding at December 31, 2015		562,000			11.91		2.51		17,456,220
Grants		-			-		-		-
Exercised		(265,000	)		2.68		-		9,392,150
Forfeitures or expirations		-			-		-		-
Outstanding at December 31, 2016		297,000			20.14		3.10		10,561,380

Vested and expected to vest at December 31, 2016		297,000			20.14		3.10		10,561,380
Exercisable at December 31, 2016		250,750		$	17.88		2.60	$	9,483,518

The following table summarizes information relating to stock options by exercise price at December 31, 2016:

	Outstanding Shares						Exercisable Shares
Option Exercise Price	Number of Shares		Weighted Average Life (years)		Weighted Average Exercise Price		Number of Shares		Weighted Average Option Price		Weighted Average Life (years)
4.00 - 5.50		35,000		0.71	$	5.24		35,000	$	5.24		0.71
13.24 - 15.85		60,000		3.58		14.61		60,000		14.61		3.58
17.00 - 21.00		125,000		2.39		19.69		121,250		19.74		2.26
26.43 - 37.64		77,000		4.97		31.95		34,500		29.83		3.99
		297,000		3.10	$	20.14		250,750	$	17.88		2.60