Stock Options (Tables)

6 Months Ended

Jun. 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 six months ended June 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		1,988,500			7.82
Exercised		(89,069	)		3.40
Forfeited		(275,406	)		7.78
Outstanding at June 30, 2018		9,468,991		$	4.49		3.41	$	18,702,009
Vested at June 30, 2018		5,362,440		$	2.58		2.07	$	16,383,991