Stock-Based Compensation (Tables)

6 Months Ended

Mar. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summarized Information about Stock Options

The following table summarizes information about stock options:

	Number of Options Outstanding			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term	Aggregate Intrinsic Value
Balance At September 30, 2018		5,524,399		$	6.14
Granted		712,500		13.26
Cancelled		(47,557	)	7.01
Exercised		(702,242	)	5.23
Balance At March 31, 2019		5,487,100		$	7.17	6.0 years	$	61,552,640
Exercisable At March 31, 2019		4,052,157		$	6.26	5.0 years	$	49,183,457

Assumptions Used to Value Stock Options

The assumptions used to value stock options are as follows:

	Six Months Ended March 31,
	2019	2018
Dividend yield	—	—
Risk-free interest rate	2.3 – 3.1%	2.1 – 2.7%
Volatility	115%	110%
Expected life (in years)	6.25	6.25
Weighted average grant date fair value per share of options granted	$11.42	$3.47

Summary of Share Activity Related to RSUs

The following table summarizes the activity of the Company’s RSUs:

	Number of RSUs			Weighted- Average Grant Date Fair Value
Unvested at September 30, 2018		2,968,500		$	2.99
Granted		1,403,888			12.43
Vested		(2,197,305	)		2.78
Forfeited		(123,750	)		8.98
Unvested at March 31, 2019		2,051,333		$	9.32