Stock Options (Tables)

9 Months Ended

Sep. 30, 2018

The weighted average assumptions used principally in determining the fair value of options granted to employees were as follows:

A summary of option activity for the nine months ended September 30, 2018 and is presented below:

Options	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term in Years		Aggregate Intrinsic Value
Outstanding at December 31, 2017		7,844,966		$	3.75
Granted		2,138,500			7.62
Exercised		(129,069	)		2.62
Forfeited		(420,156	)		7.85
Outstanding at September 30, 2018		9,434,241		$	4.46		7.45	$	32,456,058
Vested at September 30, 2018		5,671,042		$	2.73		6.61	$	28,253,546