4. CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES

The following table summarizes the Company’s financial assets with maturities of less than 90 days from the date of purchase included in cash equivalents in the unaudited condensed consolidated balance sheets for each of the periods indicated:

	As of March 31, 2018		As of December 31, 2017
	(in thousands)
Money market funds		370,052		352,370
Corporate bonds		24,451		16,720
Government and government agency bonds		24,981		49,972
Total		419,484		419,062

It is the Company’s policy to mitigate credit risk in its financial assets by maintaining a well-diversified portfolio that limits the amount of exposure as to maturity and investment type. The weighted average maturity of the Company’s available-for-sale securities as of March 31, 2018 and December 31, 2017 was approximately three and seven months, respectively.

The following tables summarize the Company’s cash, cash equivalents and short-term investments for each of the periods indicated:

	As of March 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
	(in thousands)
Cash and money market funds	$	507,802	$	—	$	—		$	507,802
Commercial paper		178,875		—		—			178,875
Government and government agency bonds		270,422		1		(304	)		270,119
Corporate bonds		92,535		—		(340	)		92,195
Total assets	$	1,049,634	$	1	$	(644	)	$	1,048,991
As reported:
Cash and cash equivalents	$	557,233	$	1	$	—		$	557,234
Short-term investments	$	492,401	$	—	$	(644	)	$	491,757
Total assets	$	1,049,634	$	1	$	(644	)	$	1,048,991

	As of December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
	(in thousands)
Cash and money market funds	$	532,999	$	—	$	—		$	532,999
Commercial paper - current		133,368		—		—			133,368
Government and government agency bonds - current		294,915		2		(200	)		294,717
Corporate bonds				—				$	—
Current		118,121		—		(145	)		117,976
Non-current		10,016		—		(36	)		9,980
Total assets	$	1,089,419	$	2	$	(381	)	$	1,089,040
As reported:
Cash and cash equivalents	$	599,698	$	2	$	(9	)	$	599,691
Short-term investments		479,705		—		(336	)		479,369
Long-term investments		10,016		—		(36	)		9,980
Total assets	$	1,089,419	$	2	$	(381	)	$	1,089,040