Fair value of financial assets and liabilities (Tables)

12 Months Ended

Mar. 31, 2020

Fair value of financial assets and liabilities

Schedule of company's financial assets and liabilities measured at fair value on a recurring basis

	Fair Value Measurements
	as of March 31, 2020 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	36,712	$	—	$	36,712
Commercial paper		—		21,884		—		21,884
US Treasury bonds		—		35,810		—		35,810
US Government Agency bonds		—		15,295		—		15,295
Corporate debt securities		—		36,066		—		36,066
	$	—	$	145,767	$	—	$	145,767

	Fair Value Measurements
	as of March 31, 2019 Using:
	Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	—	$	2,676	$	—	$	2,676
Commercial paper		—		46,687		—		46,687
US Government Agency bonds		—		20,884		—		20,884
US Treasury bonds		—		41,057		—		41,057
Corporate debt securities		—		8,467		—		8,467
	$	—	$	119,771	$	—	$	119,771

Schedule of unobservable inputs of the warrant liability upon the conversion date

		Year Ended
		March 31, 2019
Risk-free interest rate		2.81	%
Expected term (in years)		7.2
Expected volatility		64.4	%
Expected dividend yield		0	%
Fair value of series seed preferred stock	$	15.00

Schedule of roll forward of the warrant liability

	Warrant
	Liability
Balance at March 31, 2018	$	1,642
Change in fair value		5,452
Conversion of convertible preferred stock warrant into common stock warrant		(7,094)
Balance at March 31, 2019	$	—