Redeemable Convertible Preferred Stock Warrant Liability (Tables)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Schedule of Stockholders' Equity Note, Warrants or Rights

The following table sets forth a summary of the changes in the estimated fair value of the Company’s redeemable convertible preferred stock warrants, which represents financial instruments with valuations classified as

Level 3. When a determination is made to classify a financial instrument within Level 3, the determination is based upon the significance of the unobservable inputs to the overall fair value measurement. However, Level 3 financial instruments typically include, in addition to the unobservable inputs, observable inputs (that is, components that are actively quoted and can be validated to external sources). Accordingly, the gain or loss in the table below includes changes in fair value due in part to observable factors that are part of the Level 3 methodology recognized in the statement of operations as a component of interest and other income or expense as appropriate (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Beginning of the period	$	129	$	749	$	177	$	870
Exercised	(112)		(532)		(113)		(653)
Cancelled	(16)		(22)		(16)		(22)
Change in fair value	(1)		(67)		(48)		(67)
End of the period	$	—	$	128	$	—	$	128

Warrants to purchase shares of redeemable convertible preferred stock outstanding and exercisable are as follows (in thousands, except per share data):

				Shares Outstanding at			Fair Value at
Dates			Exercise Price	September 30,	December 31,	Initial Value	September 30,		December 31,
Issuance	Expiration	Series		2021	2020		2021		2020
Jun 2017	Jun 2022	E	13.73	—	72	763	$	—	$	177