Net Loss Per Share (Tables)

12 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table presents the computation of basic and diluted net loss per share for the years ended September 30, 2024, 2023 and 2022.

	Year Ended September 30,
	2024		2023		2022
	(in thousands, except per share amounts)
Numerator:
Net loss attributable to Arrowhead Pharmaceuticals, Inc.	$	(599,493)	$	(205,275)	$	(176,063)
Denominator:
Weighted-average basic shares outstanding	119,784		106,750		105,426
Effect of dilutive securities	—		—		—
Weighted-average diluted shares outstanding	119,784		106,750		105,426
Basic net loss per share	$	(5.00)	$	(1.92)	$	(1.67)
Diluted net loss per share	$	(5.00)	$	(1.92)	$	(1.67)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following table sets forth the potentially dilutive securities that have been excluded from the calculation of diluted net loss per share because to include them would be anti-dilutive.

	Year Ended September 30,
	2024	2023	2022
	(in thousands)
Options	707	633	533
Restricted stock units	4,030	3,420	3,352
Total	4,737	4,053	3,885