Stock-based compensation (Tables)

3 Months Ended

Mar. 31, 2016

Stock option activity for the three months ended March 31, 2016 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, 2015	1,268,200		$1.20-$5.39	$	3.06	6.01 years	$	985,578
Granted	5,000		3.93	3.93
Exercised	—		—	—
Canceled and forfeited	(150,000	)	3.39	3.39
Expired	—		—	—
Outstanding, March 31, 2016	1,123,200		$1.20-$5.39	$	3.02	5.46 years	$	1,300,361
Exercisable, March 31, 2016	849,558			$	2.50		$	1,286,161
Vested and expected to vest, March 31, 2016	1,123,200			$	3.02		$	1,300,361