Investments

Available-for-Sale Securities

The amortized cost and fair value of available-for-sale investments as of April 1, 2018 were as follows:



(in thousands)	Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. government treasuries and agencies securities	$	61,166		$	—	$	(894	)	$	60,272
Money market funds	48,847			—		—			48,847
Asset-backed securities	16,797			—		(110		)	16,687
Corporate bonds	111,266			43		(1,704		)	109,605
International government bonds	2,650			—		(12		)	2,638
Corporate commercial paper	9,034			—		—			9,034
Bank deposits	45,080			—		—			45,080
Repurchase agreements	142			—		—			142
Total available-for-sale investments	294,982			43		(2,720		)	292,305
Less amounts classified as cash equivalents	(70,279		)	—		—			(70,279		)
Short-term investments	$	224,703		$	43	$	(2,720	)	$	222,026

The amortized cost and fair value of available-for-sale investments as of April 2, 2017 were as follows:



(in thousands)	Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. government treasuries and agencies securities	$	62,048		$	16	$	(508	)	$	61,556
Money market funds	140,425			—		—			140,425
Asset-backed securities	13,865			5		(23		)	13,847
Corporate bonds	96,660			42		(326		)	96,376
International government bonds	5,423			2		(15		)	5,410
Corporate commercial paper	4,898			—		—			4,898
Bank deposits	12,305			—		—			12,305
Repurchase agreements	173			—		—			173
Total available-for-sale investments	335,797			65		(872		)	334,990
Less amounts classified as cash equivalents	(143,498		)	—		—			(143,498		)
Short-term investments	$	192,299		$	65	$	(872	)	$	191,492

The cost and estimated fair value of available-for-sale debt securities as of April 1, 2018, by contractual maturity, were as follows:



(in thousands)	Amortized Cost		Estimated Fair Value
Due in 1 year or less	$	119,172	$	119,056
Due in 1-2 years	111,814		110,226
Due in 2-5 years	63,996		63,023
Total investments in available-for-sale debt securities	$	294,982	$	292,305

The cost and estimated fair value of available-for-sale debt securities as of April 2, 2017, by contractual maturity, were as follows:



(in thousands)	Amortized Cost		Estimated Fair Value
Due in 1 year or less	$	188,008	$	187,984
Due in 1-2 years	46,089		45,995
Due in 2-5 years	101,700		101,011
Total investments in available-for-sale debt securities	$	335,797	$	334,990

The following table shows the gross unrealized losses and fair value of the Company’s investments with unrealized losses as of April 1, 2018, aggregated by investment category and length of time that individual securities have been in a continuous loss position.



	Less Than 12 Months					12 Months or Greater					Total
(in thousands)	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
Corporate bonds	$	78,726	$	(1,324	)	$	23,286	$	(380	)	$	102,012	$	(1,704	)
U.S. government treasuries and agencies securities	25,352		(221		)	34,920		(673		)	60,272		(894		)
Asset-backed securities	14,147		(90		)	2,540		(20		)	16,687		(110		)
International government bonds	—		—			2,638		(12		)	2,638		(12		)
Total	$	118,225	$	(1,635	)	$	63,384	$	(1,085	)	$	181,609	$	(2,720	)

The following table shows the gross unrealized losses and fair value of the Company’s investments with unrealized losses, as of April 2, 2017, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position.



	Less Than 12 Months					12 Months or Greater				Total
(in thousands)	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Corporate bonds	$	71,308	$	(326	)	$	—	$	—	$	71,308	$	(326	)
Asset-backed securities	11,294		(23		)	—		—		11,294		(23		)
U.S. government treasuries and agencies securities	55,497		(508		)	—		—		55,497		(508		)
International government bonds	2,634		(15		)	—		—		2,634		(15		)
Total	$	140,733	$	(872	)	$	—	$	—	$	140,733	$	(872	)

Currently, a significant portion of the Company’s available-for-sale investments that it holds are high grade instruments. As of April 1, 2018, the unrealized losses on the Company’s available-for-sale investments represented an insignificant amount in relation to its total available-for-sale portfolio. Substantially all of the Company’s unrealized losses on its available-for-sale marketable debt instruments can be attributed to fair value fluctuations in an unstable credit environment that resulted in a decrease in the market liquidity for debt instruments. Because the Company has the ability to hold these investments until a recovery of fair value, which may be maturity, the Company did not consider these investments to be other-than-temporarily impaired as of April 1, 2018 or April 2, 2017.

Non-marketable Equity Securities

As of April 1, 2018 and April 2, 2017, the Company holds capital stock of privately-held companies with total amount of $27.3 million and $13.2 million, respectively. During fiscal 2018, the Company purchased common stock of privately-held companies for $14.1 million. These investments in stocks (included in Other Assets on the Consolidated Balance Sheet) are accounted for as cost-method investments, as the Company owns less than 20% of the voting securities and does not have the ability to exercise significant influence over operating and financial policies of each entity.

The Company did not record any impairment charge for these investments in fiscal 2018, 2017 and 2016.