Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Financial Liabilities Measure on a Recurring Basis

The following tables sets forth by level within the fair value hierarchy the Company’s assets and liabilities that are reported at fair value as of December 31, 2019 and 2018, using the inputs defined above (in thousands):

	December 31, 2019
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	34,363	$	—	$	—	$	34,363
Commercial paper	—		9,919		—		9,919
Corporate bonds/notes	—		10,176		—		10,176
U.S. government securities	—		44,456		—		44,456
Asset-backed securities	—		5,181		—		5,181
	$	34,363	$	69,732	$	—	$	104,095

	December 31, 2018
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	10,495	$	—	$	—	$	10,495
Liabilities:
Redeemable convertible warrant liability	$	—	$	—	$	16,091	$	16,091

Option Pricing Model Assumptions

Additionally, the model’s inputs reflected assumptions that market participants would use in pricing the instrument in a current period transaction and included:

	December 31,
	2018
Time to liquidity (years)	0.57
Expected volatility	62.5%
Discounted cash flow rate	12.0%
Risk-free interest rate	2.6%
Marketability discount rate	14%

Changes in the Redeemable Convertible Warrant Liability

Fair value at December 31, 2017	$	4,185
Change in fair value recorded in other income (expense), net	11,906
Fair value at December 31, 2018	16,091
Change in fair value recorded in other income (expense), net	21,030
Reclassification upon IPO	(37,121)
Fair Value at December 31, 2019	$	—