Marketable Securities

All of our cash equivalents and marketable securities are classified as “available-for-sale” securities. These securities are reported at fair value with the related unrealized gains and losses included in accumulated other comprehensive income (loss), a component of shareholders’ equity, net of tax, and net realized gains and losses recorded in other income, net, on the Consolidated Statements of Income.

The following is a summary of cash equivalents and marketable securities as of January 31, 2016 and January 25, 2015:



	January 31, 2016
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In millions)
Corporate debt securities	$	1,903	$	1	$	(3	)	$	1,901
Debt securities of United States government agencies	1,170		1		(1		)	1,170
Debt securities issued by United States Treasury	800		1		—			801
Asset-backed securities	435		—		—			435
Mortgage backed securities issued by United States government-sponsored enterprises	229		3		(1		)	231
Foreign government bonds	92		—		—			92
Money market funds	43		—		—			43
Total	$	4,672	$	6	$	(5	)	$	4,673
Classified as:
Cash equivalents								$	232
Marketable securities								4,441
Total								$	4,673



	January 25, 2015
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In millions)
Corporate debt securities	$	2,185	$	3	$	(2	)	$	2,186
Debt securities of United States government agencies	750		—		—			750
Debt securities issued by United States Treasury	534		3		—			537
Asset-backed securities	453		—		—			453
Mortgage backed securities issued by United States government-sponsored enterprises	274		5		(1		)	278
Money market funds	132		—		—			132
Foreign government bonds	85		—		—			85
Total	$	4,413	$	11	$	(3	)	$	4,421
Classified as:
Cash equivalents								$	295
Marketable securities								4,126
Total								$	4,421

The following table provides the breakdown of the investments with unrealized losses as of January 31, 2016:



	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(In millions)
Corporate debt securities	$	950	$	(3	)	$	80	$	—	$	1,030	$	(3	)
Debt securities issued by United States government agencies	692		(1		)	—		—		692		(1		)
Mortgage backed securities issued by United States government-sponsored enterprises	97		(1		)	31		—		128		(1		)
Total	$	1,739	$	(5	)	$	111	$	—	$	1,850	$	(5	)

We performed an impairment review of our investment portfolio as of January 31, 2016. Factors considered included general market conditions, the duration and extent to which fair value is below cost, and our intent and ability to hold an investment for a sufficient period of time to allow for recovery in value. We also consider specific adverse conditions related to the financial health of and business outlook for an investee, including industry and sector performance, changes in technology, operational and financing cash flow factors, and changes in an investee’s credit rating. Investments that we identify as having an indicator of impairment are subject to further analysis to determine if the investment was other than temporarily impaired. Based on our quarterly impairment review and having considered the guidance in the relevant accounting literature, we concluded that our investments were appropriately valued and that no other-than-temporary impairment charges were necessary on our portfolio of available-for-sale investments as of January 31, 2016.

As of January 31, 2016, we had nine investments that were in an unrealized loss position with total unrealized losses amounting to $5 million and with a duration of less than one year. The gross unrealized losses related to fixed income securities were due to changes in interest rates. We have determined that the gross unrealized losses on investment securities as of January 31, 2016 are temporary in nature. Currently, we have the intent and ability to hold our investments with impairment indicators until maturity.

Net realized gains were $2 million for both fiscal year 2016 and 2014 and were not significant for fiscal year 2015. As of January 31, 2016, net unrealized gain was not significant. As of January 25, 2015, we had a net unrealized gain of $8 million, which was comprised of gross unrealized gains of $11 million, offset by $3 million of gross unrealized losses.

The amortized cost and estimated fair value of cash equivalents and marketable securities, which are primarily debt instruments, are classified as available-for-sale as of January 31, 2016 and January 25, 2015 and are shown below by contractual maturity.



	January 31, 2016				January 25, 2015
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(In millions)
Less than one year	$	1,619	$	1,619	$	1,570	$	1,570
Due in 1 - 5 years	3,019		3,020		2,720		2,726
Mortgage-backed securities issued by government-sponsored enterprises not due at a single maturity date	34		34		123		125
Total	$	4,672	$	4,673	$	4,413	$	4,421