Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Financial Instruments Measured at Fair Value on Recurring Basis

The following tables summarize the Company’s financial instruments measured at fair value on a recurring basis (in thousands):

			Fair Value Measurements At Reporting Date Using
	Total		Quoted Prices in Active Markets For Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of December 31, 2020
Assets:
Commercial paper	$	27,136	$	—	$	27,136	$	—
Corporate debt securities		26,506		—		26,506		—
U.S. government and agency securities		18,141		—		18,141		—
Total assets measured at fair value	$	71,783	$	—	$	71,783	$	—
As of December 31, 2019
Assets:
Commercial paper	$	9,694	$	—	$	9,694	$	—
Corporate debt securities		24,781		—		24,781		—
Asset backed securities		5,508		—		5,508		—
Total assets measured at fair value	$	39,983	$	—	$	39,983	$	—
Liabilities:
Preferred stock warrant liability	$	184	$	—	$	—	$	184

Summary of Assumptions Used in Black-Scholes Option Pricing Model to Determine Fair Value of Warrant Liability

The assumptions used in the Black-Scholes option pricing model to determine the fair value of the warrant liability were as follows:

	September 15, 2020 (Conversion Date)			December 31, 2019
Fair value of underlying preferred stock	$	13.00		$	9.79
Exercise price	$	10.812		$	10.812
Risk-free interest rate		0.7	%		1.9	%
Expected volatility		93.3	%		80.0	%
Expected term (in years)		9.0			9.7
Expected dividend yield		—			—

Summary of Reconciliation of Warrant Liability Measured at Fair Value Using Level 3 Significant Unobservable Inputs

The following table provides a reconciliation of the warrant liability measured at fair value using Level 3 significant unobservable inputs (in thousands):

	Warrant Liability
Balance at December 31, 2019	$	184
Change in fair value of warrant liability		75
Conversion to common stock warrant upon completion of IPO		(259	)
Balance at December 31, 2020	$	—