Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2020

Summary of Fair Value of Financial Instrument

The following tables summarize the fair value of the Company’s financial instruments (in thousands):

			Fair Value Measurements Using
	September 30, 2020		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents:
Money market funds	$	186,308	$	186,308	$	—	$	—
Short-term investments:
Corporate debt securities	$	41,957		—	$	41,957		—
Commercial paper		53,922		—		53,922		—
U.S. treasury bills		45,312		—		45,312		—
Total short-term investments		141,191		—		141,191		—
Total	$	327,499	$	186,308	$	141,191	$	—

			Fair Value Measurements Using
	December 31, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents:
Commercial paper	$	2,395	$	—	$	2,395	$	—
Short-term investments:
Corporate debt securities	$	6,027		—	$	6,027		—
Commercial paper		10,357		—		10,357		—
Total short-term investments		16,384		—		16,384		—
Total	$	18,779	$	—	$	18,779	$	—
Liabilities:
Preferred stock purchase right liability	$	1,478	$	—	$	—	$	1,478

Schedule of Change in Preferred Stock Purchase Right Liability

The following table provides the change in preferred stock purchase right liability for the nine months ended September 30, 2020 (in thousands):

	Preferred Stock Purchase Right Liability
Balance, December 31, 2019	$	1,478
Change in fair value of preferred stock purchase right		40,163
Reclassification of preferred stock purchase right liability    to equity upon issuance of convertible preferred stock		(41,641	)
Balance, September 30, 2020	$	—

Short-term investments

Schedule of Short-term Investments Accounted as Available-for-sale Securities

The following tables summarize the Company’s short-term investments accounted for as available-for-sale securities as of September 30, 2020 and December 31, 2019 (in thousands):

		September 30, 2020
	Maturity (in years)	Amortized Cost		Unrealized Losses			Unrealized Gains		Estimated Fair Value
Corporate debt securities	1 year or less	$	41,959	$	(6	)	$	4	$	41,957
Commercial paper	1 year or less		53,922		—			—		53,922
U.S. treasury bills	1 year or less		45,307		(1	)		6		45,312
Total		$	141,188	$	(7	)	$	10	$	141,191

		December 31, 2019
	Maturity (in years)	Amortized Cost		Unrealized Losses			Unrealized Gains		Estimated Fair Value
Corporate debt securities	1 year or less	$	6,029	$	(2	)	$	—	$	6,027
Commercial paper	1 year or less		10,357		—			—		10,357
Total		$	16,386	$	(2	)	$	—	$	16,384