Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Stock option activity for the three months ended March 31, 2018 was as follows:



Common Stock Options	Number of Options		Exercise Price Per Share	Weighted Average Exercise Price		Weighted Average Remaining Life	Aggregate Intrinsic Value
Outstanding, December 31, 2017	1,061,552		$0.79-$18.15	$	3.60	4.95 years	$	291,449
Granted	37,000		$2.30-$2.70	$2.43
Exercised	(40,204	)	$1.20	$1.20
Canceled and forfeited	(35,609	)	$2.60-$6.74	$4.31
Outstanding, March 31, 2018	1,022,739		$0.79-$18.15	$	3.62	5.41 years	$	312,550
Exercisable, March 31, 2018	811,864			$	3.54		$	296,630
Vested and expected to vest, March 31, 2018	991,108			$	3.61		$	312,550