Marketable securities

6 Months Ended

Jun. 30, 2022

Marketable securities as of June 30, 2022 consisted of the following (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable securities, current:
Corporate debt securities	$	210,758	$	—	$	(1,723)	$	209,035
U.S. government debt securities	20,989		—		(257)		20,732
U.S. Treasury securities	21,023		—		(306)		20,717
Marketable securities, non-current:
Corporate debt securities	56,256		—		(1,220)		55,036
U.S. government debt securities	30,988		—		(941)		30,047
U.S. Treasury securities	5,108		—		(134)		4,974
Total marketable securities, current and non-current	$	345,122	$	—	$	(4,581)	$	340,541

Marketable securities as of December 31, 2021 consisted of the following (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable securities, current:
Corporate debt securities	$	219,414	$	1	$	(250)	$	219,165
U.S. Treasury securities	8,987		—		(3)		8,984
U.S. government debt securities	5,006		—		—		5,006
Marketable securities, non-current:
Corporate debt securities	89,538		—		(403)		89,135
U.S. government debt securities	32,982		—		(105)		32,877
U.S. Treasury securities	20,203		—		(15)		20,188
Total marketable securities, current	$	376,130	$	1	$	(776)	$	375,355

Marketable securities classified as current have maturities of less than one year. Marketable securities classified as non-current are those that: (i) have a maturity of greater than one year, and (ii) we do not intend to liquidate within the next twelve months, although these funds are available for use and, therefore, are classified as available-for-sale. No available-for-sale debt securities held as of June 30, 2022 or December 31, 2021 had remaining maturities greater than five years.

Marketable securities in unrealized loss positions as of June 30, 2022 consisted of the following (in thousands, except number of securities):


	Number of Securities	Fair Value		Gross Unrealized Losses
Marketable securities in continuous unrealized loss position for less than 12 months:
Corporate debt securities	95	$	242,455	$	(2,743)
U.S. government debt securities	10	45,908		(1,069)
U.S. Treasury securities	6	25,691		(440)
Marketable securities in continuous unrealized loss position for greater than 12 months:
Corporate debt securities	11	20,186		(200)
U.S. government debt securities	1	4,871		(129)
Total marketable securities in unrealized loss position	123	$	339,111	$	(4,581)

There were no individual securities that were in a significant unrealized loss position as of June 30, 2022, and, based on factors such as historical experience, market data, issuer-specific factors, and current economic conditions, the Company

did not record an allowance for credit losses as of June 30, 2022 related to these securities. Further, given the lack of significant change in the credit risk, the Company does not consider these marketable securities to be impaired.

As of December 31, 2021, no marketable securities were in a continuous unrealized loss position for 12 months or longer.