The following table presents the Company’s cash, cash equivalents, restricted cash, and marketable securities as of December 31, 2019 and 2018 (in thousands):


	December 31, 2019
	Adjusted		Unrealized		Unrealized				Cash and Cash		Restricted		Marketable
	Cost		Gains		Losses		Fair Value		Equivalents		Cash		Securities
Cash	$	9,302	$	—	$	—	$	9,302	$	7,993	$	1,309	$	—
Level 1 (1):
Money market funds		18,306		—		—		18,306		18,306		—		—
U.S. treasury securities		5,996		—		—		5,996		2,496		—		3,500
Subtotal		24,302		—		—		24,302		20,802		—		3,500
Level 2 (2):
U.S. government agency securities		3,510		—		—		3,510		3,510		—		—
Total	$	37,114	$	—	$	—	$	37,114	$	32,305	$	1,309	$	3,500


	December 31, 2018
	Adjusted		Unrealized		Unrealized				Cash and Cash		Restricted		Marketable
	Cost		Gains		Losses		Fair Value		Equivalents		Cash		Securities
Cash	$	10,992	$	—	$	—	$	10,992	$	9,689	$	1,303	$	—
Level 1 (1):
Money market funds		23,203		—		—		23,203		23,203		—		—
U.S. treasury securities		18,938		—		(4)		18,934		—		—		18,934
Subtotal		42,141		—		(4)		42,137		23,203		—		18,934
Level 2 (2):
U.S. government agency securities		9,661		—		(5)		9,656		—		—		9,656
Total	$	62,794	$	—	$	(9)	$	62,785	$	32,892	$	1,303	$	28,590

(1)

The fair value of Level 1 securities is estimated based on quoted prices in active markets for identical assets or liabilities.

(2)

The fair value of Level 2 securities is estimated based on observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term on the assets or liabilities.