Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and liabilities measured at fair value on a recurring basis as of September 30, 2020 are as follows:

	Total		Level 1		Level 2		Level 3
Assets
Cash equivalents:
Money market funds	$	3,961	$	3,961	$	—	$	—
Short-term investments:
Commercial paper	14,943		—		14,943		—
Corporate notes/bonds	44,126		—		44,126		—
U.S. Treasuries	2,265		—		2,265		—
U.S. government agency securities	1,287		—		1,287		—
Total financial assets	$	66,582	$	3,961	$	62,621	$	—
Liabilities
Common stock warrant liability	$	71	$	—	$	—	$	71
Total financial liabilities	$	71	$	—	$	—	$	71

Assets and liabilities measured at fair value on a recurring basis as of December 31, 2019 are as follows:

	Total		Level 1		Level 2		Level 3
Assets
Cash equivalents:
Money market funds	$	31,078	$	31,078	$	—	$	—
Commercial paper	2,498		—		2,498		—
Short-term investments:
Commercial paper	11,433		—		11,433		—
Corporate notes/bonds	36,597		—		36,597		—
U.S. Treasuries	4,512		—		4,512		—
U.S. government agency securities	9,784		—		9,784		—
Total financial assets	$	95,902	$	31,078	$	64,824	$	—
Liabilities
Common stock warrant liability	$	414	$	—	$	—	$	414
Total financial liabilities	$	414	$	—	$	—	$	414

Schedule of Assumptions Used to Estimate Fair Value of Warrant Liability

The following weighted-average assumptions were used to estimate the fair value of the common stock warrant liability at September 30, 2020:

	September 30, 2020
Expected term	0.5 years
Risk-free interest rate	0.1	%
Expected volatility	88.97	%
Expected dividend yield	—	%

Reconciliation of Liabilities Measured at Fair Value on a Recurring Basis

The following is a reconciliation of the Company’s liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3) for the three months ended September 30, 2020:

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Common Stock Warrant Liability
Balance at December 31, 2019	$	414
Additions
Gain included in other income (expense), net	(343)
Balance at September 30, 2020	$	71