Stock-based compensation (Tables)

3 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Schedule of Nonvested Restricted Stock Units Activity

Activity with respect to the Company’s restricted stock units during the three months ended December 31, 2023 was as follows:

(in thousands, except per share data)	Shares	Weighted average grant date fair value per share
Nonvested shares at September 30, 2023	1,620	$	40.73
Granted	1,035	22.14
Vested/Issued	(152)	43.58
Forfeited	(84)	50.29
Nonvested shares at December 31, 2023	2,419	$	32.29

Schedule of Nonvested Performance-based Units Activity

Activity under the PSUs during the three months ended December 31, 2023 is summarized below:

(in thousands, except per share data)	Shares	Weighted average grant date fair value per share
Nonvested shares at September 30, 2023	932	$	36.82
Granted	570	17.31
Vested/Issued	(82)	80.27
Forfeited	(15)	48.37
Nonvested shares at December 31, 2023	1,405	$	26.23

Schedule of Activity Under Option and Performance Stock Options

Options activity during the three months ended December 31, 2023 is summarized below:

(in thousands, except per share data)	Shares	Weighted average exercise price per share		Weighted average remaining contractual term (years)	Aggregate intrinsic value
Outstanding at September 30, 2023	2,119	$	24.18	5.25	$	6,715
Forfeited	(85)	34.45		—	—
Exercised	(58)	16.42		—	483
Outstanding at December 31, 2023	1,976	$	23.97	1.86	$	29,951
Nonvested at December 31, 2023	19	77.89		5.48	5
Exercisable at December 31, 2023	1,958	$	23.46	1.82	$	29,946

Activity under the PSOs during the three months ended December 31, 2023 is summarized below:

(in thousands, except per share data)	Shares	Weighted average exercise price per share		Weighted average remaining contractual term (years)	Aggregate intrinsic value
Outstanding at September 30, 2023	289	$	60.82	7.37	$	—
Nonvested at September 30, 2023	30	$	31.29	8.57	$	—
Exercisable at September 30, 2023	259	64.24		7.23	—
Forfeited	(12)	$	67.85	—	$	—
Exercisable at December 31, 2023	247	$	64.07	6.99	$	251
Nonvested at December 31, 2023	30	31.29		8.32	167
Outstanding at December 31, 2023	277	$	60.53	7.13	$	418

Schedule of Stock-Based Compensation Expenses

Total stock-based compensation expense/(credit) recognized was as follows:

	Three months ended December 31,
(in thousands)	2023		2022
Cost of revenues	$	924	$	1,142
Research and development	2,838		4,418
Selling, general and administrative	7,258		(7,885)
Total stock-based compensation	$	11,020	$	(2,325)

Summary of Stock Option Valuation Assumptions

The number of shares reserved for issuance at December 31, 2023 was as follows:

(In thousands)	Shares available
Outstanding at September 30, 2023	539
Additional shares authorized	249
Shares issued during the period	—
Outstanding at December 31, 2023	788