Financial Instruments

The following is a summary of cash equivalents and available-for-sale securities as of the end of the periods presented:



	June 28, 2014									March 29, 2014
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Money market funds	$	174,031	$	—	$	—		$	174,031	$	213,988	$	—	$	—		$	213,988
Financial institution
securities	254,969		—		—			254,969		366,906		—		—			366,906
Non-financial institution
securities	621,880		4,470		(344		)	626,006		753,888		3,428		(1,244		)	756,072
Auction rate securities	21,500		—		(796		)	20,704		21,500		—		(1,340		)	20,160
Municipal bonds	38,164		820		(143		)	38,841		31,367		604		(205		)	31,766
U.S. government and
agency securities	593,637		1,145		(80		)	594,702		548,568		1,135		(184		)	549,519
Foreign government and
agency securities	410,896		—		(6		)	410,890		354,935		—		—			354,935
Mortgage-backed securities	1,225,050		14,355		(6,870		)	1,232,535		1,234,237		11,380		(10,528		)	1,235,089
Debt mutual funds	101,350		703		(2,625		)	99,428		81,350		216		(4,652		)	76,914
Bank loans	57,667		105		(65		)	57,707		—		—		—			—
	$	3,499,144	$	21,598	$	(10,929	)	$	3,509,813	$	3,606,739	$	16,763	$	(18,153	)	$	3,605,349

The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of June 28, 2014 and March 29, 2014:



	June 28, 2014
	Less Than 12 Months					12 Months or Greater					Total
(In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Non-financial institution securities	$	32,613	$	(84	)	$	19,902	$	(260	)	$	52,515	$	(344	)
Auction rate securities	—		—			20,704		(796		)	20,704		(796		)
Municipal bonds	4,026		(6		)	4,603		(137		)	8,629		(143		)
U.S. government and
agency securities	250,910		(31		)	4,369		(49		)	255,279		(80		)
Foreign government and
agency securities	124,968		(6		)	—		—			124,968		(6		)
Mortgage-backed securities	234,724		(2,223		)	274,363		(4,647		)	509,087		(6,870		)
Debt mutual fund	—		—			58,724		(2,625		)	58,724		(2,625		)
Bank loans	30,097		(65		)	—		—			30,097		(65		)
	$	677,338	$	(2,415	)	$	382,665	$	(8,514	)	$	1,060,003	$	(10,929	)



	March 29, 2014
	Less Than 12 Months					12 Months or Greater					Total
(In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
Non-financial institution securities	$	112,470	$	(1,167	)	$	4,488	$	(77	)	$	116,958	$	(1,244	)
Auction rate securities	—		—			20,160		(1,340		)	20,160		(1,340		)
Municipal bonds	5,917		(166		)	1,743		(39		)	7,660		(205		)
U.S. government and
agency securities	118,125		(184		)	—		—			118,125		(184		)
Mortgage-backed securities	457,903		(7,225		)	132,376		(3,303		)	590,279		(10,528		)
Debt mutual fund	56,698		(4,652		)	—		—			56,698		$	(4,652	)
	$	751,113	$	(13,394	)	$	158,767	$	(4,759	)	$	909,880	$	(18,153	)

As of June 28, 2014, the gross unrealized losses that had been outstanding for less than twelve months were primarily related to mortgage-backed securities due to the general rising of the interest-rate environment, although the percentage of such losses to the total estimated fair value of the mortgage-backed securities was relatively insignificant. The gross unrealized losses that had been outstanding for more than twelve months were primarily related to mortgage-backed securities and debt mutual fund, which were primarily due to the general rising of the interest-rate environment, and failed auction rate securities, which were due to adverse conditions in the global credit markets during the past five years.

The Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of June 28, 2014 and March 29, 2014 were temporary in nature as evidenced by the fluctuations in the gross unrealized losses within the investment categories. These investments are highly rated by the credit rating agencies and there have been no defaults on any of these securities, and we have received interest payments as they become due. Additionally, in the past several years a portion of the Company's investment in the auction rate securities and the mortgage-backed securities were redeemed or prepaid by the debtors at par. Furthermore, the aggregate of individual unrealized losses that had been outstanding for twelve months or more was not significant as of June 28, 2014 and March 29, 2014. The Company neither intends to sell these investments nor concludes that it is more-likely-than-not that it will have to sell them until recovery of their carrying values. The Company also believes that it will be able to collect both principal and interest amounts due to the Company at maturity, given the high credit quality of these investments and any related underlying collateral.

The amortized cost and estimated fair value of marketable debt securities (financial institution securities, non-financial institution securities, auction rate securities, municipal bonds, U.S. and foreign government and agency securities and mortgage-backed securities), by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.



	June 28, 2014
(In thousands)	Amortized Cost		Estimated Fair Value
Due in one year or less	$	1,464	$	1,464
Due after one year through five years	474		478
Due after five years through ten years	287		289
Due after ten years	999		1,005
	$	3,224	$	3,236

As of June 28, 2014, $762.4 million of marketable debt securities with contractual maturities of greater than one year were classified as short-term investments. Additionally, the above table did not include investments in money market and mutual funds because these funds do not have specific contractual maturities.

Certain information related to available-for-sale securities is as follows:



	Three Months Ended
(In thousands)	June 28, 2014			June 29, 2013
Proceeds from sale of available-for-sale securities	$	59,581		$	95,139
Gross realized gains on sale of available-for-sale securities	$	837		$	1,101
Gross realized losses on sale of available-for-sale securities	(167		)	(994		)
Net realized gains (losses) on sale of available-for-sale securities	$	670		$	107
Amortization of premiums on available-for-sale securities	$	6,233		$	7,159

The cost of securities matured or sold is based on the specific identification method.