Financial Instruments

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



	March 30, 2019									March 31, 2018
(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	$	428,150	$	—	$	—		$	428,150	$	1,291,891	$	—	$	—		$	1,291,891
Financial institution
securities	537,795		—		—			537,795		434,901		—		—			434,901
Non-financial institution
securities	702,483		3		(562		)	701,924		326,219		—		(1,376		)	324,843
U.S. government and
agency securities	334,185		39		(139		)	334,085		58,913		1		(272		)	58,642
Foreign government and
agency securities	214,455		—		—			214,455		179,957		—		—			179,957
Mortgage-backed securities	684,596		809		(14,635		)	670,770		866,048		660		(22,311		)	844,397
Asset-backed securities	76,852		—		(483		)	76,369		92,751		16		(1,378		)	91,389
Commercial mortgage-
backed securities	118,115		42		(1,618		)	116,539		156,296		1		(3,427		)	152,870
	$	3,096,631	$	893	$	(17,437	)	$	3,080,087	$	3,406,976	$	678	$	(28,764	)	$	3,378,890

Financial institution securities include securities issued or managed by financial institutions in various forms, such as commercial paper and time deposits. Substantially all time deposits were issued by institutions outside the U.S. as of March 30, 2019 and March 31, 2018.

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 March 30, 2019 and March 31, 2018:



	March 30, 2019
	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	$	4,767	$	(4	)	$	51,044	$	(558	)	$	55,811	$	(562	)
U.S. government and
agency securities	—		—			13,542		(139		)	13,542		(139		)
Mortgage-backed securities	34,595		(480		)	597,394		(14,155		)	631,989		(14,635		)
Asset-backed securities	—		—			76,103		(483		)	76,103		(483		)
Commercial mortgage-
backed securities	1,354		(3		)	112,294		(1,615		)	113,648		(1,618		)
	$	40,716	$	(487	)	$	850,377	$	(16,950	)	$	891,093	$	(17,437	)



	March 31, 2018
	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	$	69,780	$	(1,146	)	$	8,344	$	(230	)	$	78,124	$	(1,376	)
U.S. government and
agency securities	13,471		(176		)	9,176		(96		)	22,647		(272		)
Mortgage-backed securities	510,988		(11,048		)	299,663		(11,263		)	810,651		(22,311		)
Asset-backed securities	57,128		(876		)	32,696		(502		)	89,824		(1,378		)
Debt mutual funds	—		—			89,670		(11,680		)	89,670		(11,680		)
Commercial mortgage-
backed securities	95,435		(1,760		)	56,051		(1,667		)	151,486		(3,427		)
	$	746,802	$	(15,006	)	$	495,600	$	(25,438	)	$	1,242,402	$	(40,444	)

As of March 30, 2019, the gross unrealized losses that had been outstanding for both less than twelve months and more 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 Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of March 30, 2019 and March 31, 2018 were temporary in nature as evidenced by the fluctuations in the gross unrealized losses within the investment categories. The marketable debt securities (financial institution securities, non-financial institution securities, U.S. and foreign government and agency securities, asset-back securities, mortgage-backed securities and commercial mortgage-backed securities) are highly rated by the credit rating agencies, there have been no defaults on any of these securities and the Company has received interest payments as they become due. Therefore, the Company believes that it will be able to collect both principal and interest amounts due to the Company. Additionally, in the past several years a portion of the Company's investment in mortgage-backed securities was 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 March 30, 2019 and March 31, 2018. The Company neither intends to sell these marketable debt securities nor concludes that it is more-likely-than-not that it will have to sell them until recovery of their carrying values.

The amortized cost and estimated fair value of marketable debt securities, by contractual maturity, are shown in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.



	March 30, 2019
(In thousands)	Amortized Cost		Estimated Fair Value
Due in one year or less	$	1,756,125	$	1,756,001
Due after one year through five years	133,780		132,476
Due after five years through ten years	135,971		134,020
Due after ten years	642,605		629,440
	$	2,668,481	$	2,651,937

As of March 30, 2019, $895.9 million of marketable debt securities with contractual maturities of greater than one year were classified as short-term investments. Additionally, the above table does not include investments in money market and debt mutual funds because these investments do not have specific contractual maturities.

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



	Years Ended
(In thousands)	March 30, 2019			March 31, 2018			April 1, 2017
Proceeds from sale of available-for-sale and equity securities	$	35,734		$	1,161,410		$	695,030
Gross realized gains on sale of available-for-sale securities	$	372		$	7,258		$	6,989
Gross realized losses on sale of available-for-sale securities	(51		)	(7,947		)	(3,457		)
Net realized (losses) gains on sale of available-for-sale securities	$	321		$	(689	)	$	3,532
Amortization of premiums on available-for-sale securities	$	8,118		$	24,569		$	29,360

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

Starting April 1, 2018, the Company records the change in the fair value of its investment in debt mutual funds and marketable equity securities as part of its interest and other income (expense), net. This change in fair value was a net decrease of $5.0 million for the twelve months ended March 30, 2019 and the Company recorded it within interest and other income (expense), net for the period in the consolidated statements of income.