Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2021

Financial Instruments

Schedule of assets and liabilities measured fair value on recurring basis

	As of December 31, 2021
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	1,853	$	—	$	—	$	1,853
Reverse repurchase agreements		—		—		—		—
Short-term investments:
Reverse repurchase agreements		—		39,000		—		39,000
Total	$	1,853	$	39,000	$	—	$	40,853

	As of December 31, 2020
	Quoted Prices		Significant		Significant
	in Active		Observable		Unobservable
	Markets		Inputs		Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	22,999	$	—	$	—	$	22,999
Short-term investments:
Reverse repurchase agreements		—		20,000		—		20,000
Total assets	$	22,999	$	20,000	$	—	$	42,999

Summary of warrant liability was valued based on significant inputs not observable in the market, which represents a Level 3

	December 31, 2021
Balance at beginning of year	$	—
Issuance of warrants		4,332
(Decrease) increase in the fair value of the warrants		(864)
Reclassification of warrant liability to additional paid in-capital		(3,468)
Ending balance	$	—

Schedule of fair value of the warrants

	Year Ended December 31,
	2021
Weighted-average expected volatility	89.1-89.3	%
Expected term (in years)	9.54-9.88
Risk-free interest rate	1.064-1.725	%
Expected dividend yield	0	%