Fair Value of Financial Assets and Liabilities

12 Months Ended

Dec. 31, 2021

Fair Value of Financial Assets and Liabilities

Fair Value of Financial Assets and Liabilities

3.           Fair Value of Financial Assets and Liabilities

The following tables present information about the Company’s financial instruments measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values:

	Fair Value Measurements
	as of December 31, 2021 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents — money market funds	$	94,324	$	—	$	—	$	94,324
Short-term investments — U.S. Treasury notes		—		59,731		—		59,731
	$	94,324	$	59,731	$	—	$	154,055

	Fair Value Measurements
	as of December 31, 2020 Using:
	Level 1		Level 2		Level 3		Total
Assets:
Restricted cash — money market funds	$	210	$	—	$	—	$	210
Cash equivalents — money market funds		22,942		—		—		22,942
Cash equivalents — U.S. Treasury notes		—		72,695		—		72,695
Short-term investments — U.S. Treasury notes		—		209,444		—		209,444
	$	23,152	$	282,139	$	—	$	305,291

During the years ended December 31, 2021 and 2020 there were no transfers between Level 1, Level 2 and Level 3. The money market funds were valued using quoted prices in active markets, which represent a Level 1 measurement in the fair value hierarchy. The Company's cash equivalents and short-term investments as of December 31, 2021 and 2020 included U.S. Treasury notes, which are not traded on a daily basis and, therefore, represent a Level 2 measurement in the fair value hierarchy at each period end.

Cash equivalents and short-term investments as of December 31, 2021 and 2020 consisted of U.S. Treasury notes which investments were each due within six months of such date.

			Gross		Gross
	Amortized		Unrealized		Unrealized		Credit		Fair
	Cost		Gains		Losses		Losses		Value
December 31, 2021
Short-term investments — U.S. Treasury notes	$	59,745	$	1	$	(15)	$	—	$	59,731
	$	59,745	$	1	$	(15)	$	—	$	59,731

			Gross		Gross
	Amortized		Unrealized		Unrealized		Credit		Fair
	Cost		Gains		Losses		Losses		Value
December 31, 2020
Cash equivalents — U.S. Treasury notes	$	72,694	$	1	$	—	$	—	$	72,695
Short-term investments — U.S. Treasury notes		209,459		4		(19)		—		209,444
	$	282,153	$	5	$	(19)	$	—	$	282,139

As of December 31, 2021, the Company held 11securities that were in an unrealized loss position. The aggregate fair value of securities held by the Company in an unrealized loss position was $49,739 at December 31, 2021. As of December 31, 2020, the Company held 17 securities that were in an unrealized loss position. The aggregate fair value of securities held by the Company in an unrealized loss position was $107,753 at December 31, 2020. As of both December 31, 2021 and 2020 these securities were held by the Company in an unrealized loss position for less than 12 months. The Company determined that there was no material change in the credit risk of these securities. As a result, the Company determined it did not hold any investments with an other-than-temporary impairment as of December 31, 2021 and 2020.