Fair value measurement (Tables)

12 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

Cash And Cash Equivalents And Available For Sale Securities At Fair Value

The following table sets forth the cash and cash equivalents, and short-term investments as of September 30, 2020:

(in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
Cash and cash equivalents	$	93,667	$	—	$	—	$	93,667
Short-term investments		196,320		15		—		196,335
Total	$	289,987	$	15	$	—	$	290,002

The following table sets forth the cash and cash equivalents, and short-term investments as of September 30, 2019:

(in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair value
Cash and cash equivalents	$	46,735	$	—	$	—	$	46,735
Short-term investments		91,323		49		—		91,372
Total	$	138,058	$	49	$	—	$	138,107

Summary of Company's Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis

As of September 30, 2020, financial assets and liabilities measured and recognized at fair value are as follows:

(in thousands)	Level 1		Level 2		Level 3		Fair value
Assets
Cash and cash equivalents	$	20,254	$	—	$	—	$	20,254
Money market funds		73,413		—		—		73,413
Commercial paper		—		94,840		—		94,840
U.S. government treasury bills		101,495		—		—		101,495
Total	$	195,162	$	94,840	$	—	$	290,002

As of September 30, 2019, financial assets and liabilities measured and recognized at fair value are as follows:

(in thousands)	Level 1		Level 2		Level 3		Fair value
Assets
Cash and cash equivalents	$	19,344	$	—	$	—	$	19,344
Money market funds		27,390		—		—		27,390
Corporate bonds		—		8,530		—		8,530
Commercial paper		—		28,361		—		28,361
U.S. government treasury bills		54,482		—		—		54,482
Total	$	101,216	$	36,891	$	—	$	138,107

Summary of Reconciliation of Beginning and Ending Balances of the Level 3 Instruments

The following table provides a reconciliation of beginning and ending balances of the Level 3 instruments during the years ended September 30, 2020, 2019 and 2018:

(in thousands)	Series A			Series B			Series C			Series D			Total
Redeemable convertible preferred stock warrant liability:
Fair value as of September 30, 2017	$	331		$	110		$	152		$	51		$	644
Change in fair value recorded in other income (expense), net		34			(16	)		(22	)		(9	)		(13	)
Fair value as of September 30, 2018	$	365		$	94		$	130		$	42		$	631
Change in fair value recorded in other income (expense), net		(365	)		(94	)		(130	)		(42	)		(631	)
Fair value as of September 30, 2019	$	—		$	—		$	—		$	—		$	—
Change in fair value recorded in other income (expense), net		—			—			—			—			—
Fair value as of September 30, 2020	$	—		$	—		$	—		$	—		$	—