Investments

Marketable Securities

At April 30, 2018, marketable securities consisted of the following (in thousands):



	Amortized Cost		Unrealized Gains		Unrealized Losses			Aggregate Fair Value
U.S. agency obligations	$	553,880	$	—	$	(1,002	)	$	552,878
U.S. treasury securities	1,391,222		7		(1,428		)	1,389,801
Corporate bonds	420,352		19		(1,527		)	418,844
Commercial paper	760,993		—		(9		)	760,984
	$	3,126,447	$	26	$	(3,966	)	$	3,122,507
Included in cash and cash equivalents	$	792,889	$	4	$	(9	)	$	792,884
Included in marketable securities	$	2,333,558	$	22	$	(3,957	)	$	2,329,623

At January 31, 2018, marketable securities consisted of the following (in thousands):



	Amortized Cost		Unrealized Gains		Unrealized Losses			Aggregate Fair Value
U.S. agency obligations	$	683,551	$	—	$	(1,127	)	$	682,424
U.S. treasury securities	797,977		—		(1,142		)	796,835
Corporate bonds	470,259		16		(1,154		)	469,121
Commercial paper	602,727		—		—			602,727
	$	2,554,514	$	16	$	(3,423	)	$	2,551,107
Included in cash and cash equivalents	$	417,613	$	—	$	(1	)	$	417,612
Included in marketable securities	$	2,136,901	$	16	$	(3,422	)	$	2,133,495

We do not believe the unrealized losses represent other-than-temporary impairments based on our evaluation of available evidence, which includes our intent to hold these investments to maturity as of April 30, 2018. The unrealized losses on marketable securities which have been in a net loss position for 12 months or more were not material as of April 30, 2018. We classify our marketable securities as available-for-sale debt securities at the time of purchase and reevaluate such classification as of each balance sheet date. We consider all marketable securities as available for use in current operations, including those with maturity dates beyond one year, and therefore classify these securities as current assets in the accompanying condensed consolidated balance sheets. Marketable securities on the condensed consolidated balance sheets consist of securities with original maturities at the time of purchase greater than three months and the remainder of the securities is included in Cash and cash equivalents. We sold $27 million and $9 million of our marketable securities during the three months ended April 30, 2018 and 2017, respectively, and the realized gains from the sales were immaterial.

Equity Investments

Equity investments consisted of the following (in thousands):



	April 30, 2018		January 31, 2018
Marketable equity investments	$	88,571	$	551,804
Non-marketable equity investments	29,405		28,005
	$	117,976	$	579,809

Marketable equity investments consist of money market funds and are included in Cash and cash equivalents on the condensed consolidated balance sheets. During the three months ended April 30, 2018, there were no unrealized gains or losses recognized for these investments.

Non-marketable equity investments consist of investments in privately held companies without readily determinable fair values and are included in Other assets on the condensed consolidated balance sheets. During the three months ended April 30, 2018, there were no adjustments to the carrying value of the non-marketable equity investments as measured under the measurement alternative.