Fair Value Measurements (Tables)

6 Months Ended

Jun. 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 June 30, 2020 are as follows:

	Total		Level 1		Level 2		Level 3
Assets
Cash equivalents:
Money market funds	$	7,602	$	7,602	$	—	$	—
Short-term investments:
Commercial paper	15,188		—		15,188		—
Corporate notes/bonds	45,065		—		45,065		—
U.S. Treasuries	2,275		—		2,275		—
U.S. government agency securities	6,051		—		6,051		—
Total financial assets	$	76,181	$	7,602	$	68,579	$	—
Liabilities
Common stock warrant liability	$	257	$	—	$	—	$	257
Total financial liabilities	$	257	$	—	$	—	$	257

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 June 30, 2020:

	June 30, 2020
Expected term	0.8 years
Risk-free interest rate	0.2	%
Expected volatility	93.09	%
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 June 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	(157)
Balance at June 30, 2020	$	257