Stock-Based Compensation (Tables)

12 Months Ended

Sep. 30, 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		879,500		16.05
Cancelled		(87,434)		8.96
Exercised		(1,542,795)		5.36
Balance At September 30, 2019		4,773,670	$	8.16		6.0 years	$	95,727,301
Exercisable At September 30, 2019		3,515,379	$	6.58		4.9 years	$	75,931,836

Assumptions Used to Value Stock Options

The assumptions used to value stock options are as follows:

	Years ended September 30,
	2019	2018	2017
Dividend yield	—	—	—
Risk-free interest rate	1.50 – 3.11%	2.05 – 2.99%	1.34 – 2.31%
Volatility	115%	110%	79%
Expected life (in years)	6.25	6.25	5.85
Weighted average grant date fair value per share of options granted	$13.80	$5.04	$1.33

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		1,415,388			12.57
Vested		(2,197,305	)		2.78
Forfeited		(123,750	)		8.98
Unvested at September 30, 2019		2,062,833		$	9.43