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, a component of stockholders’ equity, net of tax, and net realized gains and losses recorded in other expense, net, on the Condensed Consolidated Statement of Income.

We performed an impairment review of our investment portfolio as of October 27, 2013. 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 as of October 27, 2013.

The following is a summary of cash equivalents and marketable securities at October 27, 2013 and January 27, 2013:



	October 27, 2013
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Corporate debt securities	$	1,099,456	$	2,020	$	(545	)	$	1,100,931
Debt securities of United States government agencies	726,382		798		(184		)	726,996
Debt securities issued by United States Treasury	441,075		561		(108		)	441,528
Mortgage backed securities issued by United States government-sponsored enterprises	190,993		4,129		(522		)	194,600
Asset-backed securities	60,886		6		(16		)	60,876
Money market funds	56,697		—		—			56,697
Total	$	2,575,489	$	7,514	$	(1,375	)	$	2,581,628
Classified as:
Cash equivalents								$	110,758
Marketable securities								2,470,870
Total								$	2,581,628



	January 27, 2013
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Corporate debt securities	$	1,255,297	$	3,175	$	(542	)	$	1,257,930
Debt securities of United States government agencies	867,087		1,199		(139		)	868,147
Debt securities issued by United States Treasury	785,228		1,102		(105		)	786,225
Mortgage backed securities issued by United States government-sponsored enterprises	183,034		6,194		(57		)	189,171
Asset-backed securities	—		—		—			—
Money market funds	195,790		—		—			195,790
Total	$	3,286,436	$	11,670	$	(843	)	$	3,297,263
Classified as:
Cash equivalents								$	302,166
Marketable securities								2,995,097
Total								$	3,297,263

The estimated fair value of cash equivalents and marketable securities was $2.58 billion and $3.30 billion at October 27, 2013 and January 27, 2013, respectively, a decrease of $715.6 million. This decrease was primarily due to the liquidation of a portion of our investment portfolio to fund the accelerated share repurchase transaction of $750 million that we entered into on May 14, 2013.

The following table provides the breakdown of the investments with unrealized losses at October 27, 2013:



	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 thousands)
Corporate debt securities	$	403,313	$	(16	)	$	697,618	$	(529	)	$	1,100,931	$	(545	)
Debt securities of United States government agencies	288,163		(5		)	438,833		(179		)	726,996		(184		)
Debt securities issued by United States Treasury	87,221		(42		)	354,307		(66		)	441,528		(108		)
Mortgage backed securities issued by United States government-sponsored enterprises	3,460		—			191,140		(522		)	194,600		(522		)
Asset-backed securities	10,709		(16		)	50,167		—			60,876		(16		)
Total	$	792,866	$	(79	)	$	1,732,065	$	(1,296	)	$	2,524,931	$	(1,375	)

As of October 27, 2013, we had 7 investments that were in an unrealized loss position with a duration of less than one year and 9 investments that were in an unrealized loss position with a duration of greater 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 at October 27, 2013 are temporary in nature. Currently, we have the intent and ability to hold our investments with impairment indicators until maturity.

The amortized cost and estimated fair value of cash equivalents and marketable securities which are primarily debt instruments are classified as available-for-sale at October 27, 2013 and January 27, 2013 and are shown below by contractual maturity.



	October 27, 2013				January 27, 2013
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(In thousands)
Less than 1 year	$	848,672	$	849,564	$	1,397,350	$	1,399,304
Due in 1 - 5 years	1,628,882		1,632,651		1,777,785		1,783,103
Mortgage-backed securities issued by government-sponsored enterprises not due at a single maturity date	97,935		99,413		111,301		114,856
Total	$	2,575,489	$	2,581,628	$	3,286,436	$	3,297,263

Net realized gains for the three and nine months ended October 27, 2013 were $0.1 million and $1.8 million, respectively. Net realized gains for the three and nine months ended October 28, 2012 were $0.1 million and $0.4 million, respectively.