Cash, Cash Equivalents and Marketable Securities

6 Months Ended

Jun. 30, 2018

Cash, Cash Equivalents and Marketable Securities

Cash, Cash Equivalents and Marketable Securities

4. Cash, Cash Equivalents and Marketable Securities

A summary of cash, cash equivalents and available-for-sale marketable securities held by the Company as of June 30, 2018 and December 31, 2017 is as follows (in thousands):

	June 30, 2018
			Unrealized		Unrealized		Fair
	Cost		gains		losses		value
Cash and cash equivalents:
Cash (Level 1)	$	1,615	$	—	$	—	$	1,615
Money market funds (Level 1)		230,822		—		—		230,822
Corporate debt securities due within 3 months of date of purchase (Level 2)		32,424		—		—		32,424
Total cash and cash equivalents		264,861		—		—		264,861
Marketable securities:
Corporate debt securities due within 1 year of date of purchase (Level 2)		225,487		41		(84)		225,444
Total cash, cash equivalents and marketable securities	$	490,348	$	41	$	(84)	$	490,305

	December 31, 2017
			Unrealized		Unrealized		Fair
	Cost		Gains		losses		value
Cash and cash equivalents:
Cash (Level 1)	$	2,725	$	—	$	—	$	2,725
Money market funds (Level 1)		145,902		—		—		145,902
Corporate debt securities due within 3 months of date of purchase (Level 2)		—		—		—		—
Total cash and cash equivalents		148,627		—		—		148,627
Marketable securities :
Corporate debt securities due within 1 year of date of purchase (Level 2)		42,931		—		(31)		42,900
Total cash, cash equivalents and marketable securities	$	191,558	$	—	$	(31)	$	191,527