Cash Equivalents and Marketable Securities

9 Months Ended

Sep. 30, 2021

Investments, Debt and Equity Securities [Abstract]

Cash Equivalents and Marketable Securities

At September 30, 2021, cash equivalents and marketable securities consisted of the following (in thousands):


	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Fair Value
Money market funds	$	253,079	$	—	$	—	$	253,079
Commercial paper	12,487		—		—		12,487
U.S. treasury debt securities	52,755		4		(28)		52,731
Corporate debt securities	160,945		64		(41)		160,968
Foreign government debt securities	5,037		1		—		5,038
	$	484,303	$	69	$	(69)	$	484,303
Included in cash and cash equivalents	$	253,079	$	—	$	—	$	253,079
Included in marketable securities	$	231,224	$	69	$	(69)	$	231,224

At December 31, 2020, cash equivalents and marketable securities consisted of the following (in thousands):


	Amortized Cost		Unrealized Gains		Unrealized Losses		Aggregate Fair Value
Money market funds	$	265,578	$	—	$	—	$	265,578
Commercial paper	21,489		—		—		21,489
U.S. treasury debt securities	51,731		80		(2)		51,809
Corporate debt securities	147,715		214		(47)		147,882
Foreign government debt securities	1,025		2		—		1,027
	$	487,538	$	296	$	(49)	$	487,785
Included in cash and cash equivalents	$	280,578	$	—	$	—	$	280,578
Included in marketable securities	$	206,960	$	296	$	(49)	$	207,207

The contractual maturities of the investments classified as marketable securities are as follows (in thousands):


	As of September 30, 2021
Due within one year	$	134,115
Due in one to two years	95,098
Due in three to five years	2,011
	$	231,224

The following table presents gross unrealized losses and fair values for those cash equivalents and marketable securities that were in an unrealized loss position as of September 30, 2021, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (in thousands):


	As of September 30, 2021
	Less than 12 months				12 months or greater
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U.S. treasury debt securities	$	34,768	$	(28)	$	—	$	—
Corporate debt securities	73,864		(41)		—		—
Total	$	108,632	$	(69)	$	—	$	—

We do not believe the unrealized losses represent credit losses based on our evaluation of available evidence as of September 30, 2021, which includes an assessment of whether it is more likely than not we will be required to sell the investment before recovery of the investment's amortized cost basis.