Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2019

Stockholders' Equity Note [Abstract]

Share-based Compensation, Stock Options, Activity

Warrant activity for the six months ended June 30, 2019 is presented in the table below:

	Number of Shares	Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding at December 31, 2018	353,610	$	9.78	4.36	$	1,226,833
Exercised	—	$	—
Outstanding at June 30, 2019	353,610	$	9.78	4.11	$	1,226,833
Exercisable at June 30, 2019	353,610	$	9.78	4.11	$	1,226,833

Stock option activity for options granted under the 2017 Plan during the six months ended June 30, 2019 is presented in the table below:

	Number of Shares Available		Number of Options Outstanding		Weighted-average Exercise Price		Weighted-average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Balance at December 31, 2018	157,881		343,550		$	28.97	8.95	$	840
Annual additional options authorized	153,814		—		—
Granted	(117,200	)	117,200		$	13.60
Exercised	—		—		—
Forfeited	3,600		(3,600	)	$	17.91
Balance at June 30, 2019	198,095		457,150		$	25.12	8.75	$	6,250

Stock option activity for the Pre-2017 Non-Qualified Stock Options for the six months ended June 30, 2019 is presented in the table below:

	Number of Shares		Weighted- average Exercise Price		Weighted- average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding at December 31, 2018	2,885,500		$	7.30	6.04	$	20,633,100
Exercised	(180,139	)	7.79
Forfeited	(4,861	)	10.00
Outstanding at June 30, 2019	2,700,500		$	7.27	5.49	$	16,195,750
Exercisable at June 30, 2019	2,612,436		$	7.19	5.49	$	15,865,094

Schedule of Nonvested Share Activity

A summary of the status of the Company’s non-vested options granted under the 2017 Plan as of June 30, 2019 is presented in the following table:

	Number of Shares		Weighted Average Grant Date Fair Value Per Share
Balance at June 30, 2019	457,150		$	24.29
Vested	(143,554	)	28.41
Non-vested at June 30, 2019	313,596		$	22.70

A summary of the status of the Company’s non-vested Pre-2017 Non-Qualified Stock Options as of June 30, 2019 is presented below:

	Number of Options	Weighted Average Grant Date Fair Value
Non-vested at June 30, 2019	88,064	$	7.75

Schedule of Assumptions Used in the Valuation

The assumptions used in the valuation of options granted under the 2017 Plan during the six months ended June 30, 2019 are as follows:

	For the Six Months Ended June 30, 2019
Market value of stock on measurement date	$12.75 to $14.62
Risk-free interest rate	1.88% to 2.57%
Dividend yield	—
Volatility factor	105% to 121%
Term	5.50 to 6.25 Years