Marketable Securities

9 Months Ended

Jun. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

4. Marketable Securities

As of June 30, 2022 and September 30, 2021, the fair value of available-for-sale marketable securities, by type of security, was as follows:

	June 30, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
U.S. Treasury notes	$	98,389	$	—	$	(1,213	)	$	—	$	97,176
Corporate bonds		85,969		—		(2,022	)		—		83,947
Commercial paper		83,225		—		—			—		83,225
	$	267,583	$	—	$	(3,235	)	$	—	$	264,348

	September 30, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Credit Losses		Fair Value
	(in thousands)
Corporate bonds	$	124,678	$	93	$	(68	)	$	—	$	124,703
Commercial paper		87,471		—		—			—		87,471
U.S. Treasury notes		83,061		3		(26	)		—		83,038
	$	295,210	$	96	$	(94	)	$	—	$	295,212

As of June 30, 2022 and September 30, 2021, marketable securities consisted of investments that mature within one year, with the exception of certain corporate bonds and U.S. Treasury notes, which have maturities between one and three years and an aggregate fair value of $39,427 and $108,416, respectively.