Cash, Cash Equivalents, and Investments

Cash, cash equivalents, and investments consisted of the following (in thousands):



	April 3, 2016		December 31, 2015
Cash	$	48,603	$	45,951
Money market instruments	31,311		6,024
Cash and cash equivalents	79,914		51,975
Treasury bills	106,602		109,360
Corporate bonds	74,627		54,376
Asset-backed securities	64,478		61,994
Euro liquidity fund	50,094		47,730
Sovereign bonds	22,684		21,440
Agency bonds	980		978
Municipal bonds	324		590
Short-term investments	319,789		296,468
Corporate bonds	159,221		176,575
Treasury bills	42,938		44,437
Asset-backed securities	27,115		24,582
Agency bonds	8,195		8,180
Sovereign bonds	6,805		13,503
Municipal bonds	4,544		4,869
Limited partnership interest (accounted for using cost method)	942		942
Long-term investments	249,760		273,088
	$	649,463	$	621,531

Treasury bills consist of debt securities issued by both the U.S. and foreign governments; corporate bonds consist of debt securities issued by both domestic and foreign companies; asset-backed securities consist of debt securities collateralized by pools of receivables or loans with credit enhancement; the Euro liquidity fund invests in a portfolio of investment-grade bonds; sovereign bonds consist of direct debt issued by foreign governments; agency bonds consist of domestic or foreign obligations of government agencies and government sponsored enterprises that have government backing; and municipal bonds consist of debt securities issued by state and local government entities. The Euro liquidity fund is denominated in Euros, and the remaining securities are denominated in U.S. Dollars.

The following table summarizes the Company’s available-for-sale investments as of April 3, 2016 (in thousands):



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Short-term:
Treasury bills	$	106,592	$	20	$	(10	)	$	106,602
Corporate bonds	74,589		73		(35		)	74,627
Asset-backed securities	64,508		10		(40		)	64,478
Euro liquidity fund	49,951		143		—			50,094
Sovereign bonds	22,693		1		(10		)	22,684
Agency bonds	980		—		—			980
Municipal bonds	322		2		—			324
Long-term:
Corporate bonds	159,520		392		(691		)	159,221
Treasury bills	42,868		78		(8		)	42,938
Asset-backed securities	27,150		16		(51		)	27,115
Agency bonds	8,199		—		(4		)	8,195
Sovereign bonds	6,806		3		(4		)	6,805
Municipal bonds	4,525		19		—			4,544
	$	568,703	$	757	$	(853	)	$	568,607

The following table summarizes the Company’s gross unrealized losses and fair values for available-for-sale investments in an unrealized loss position as of April 3, 2016 (in thousands):



	Unrealized Loss Position For:
	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Corporate bonds	$	85,206	$	(545	)	$	24,501	$	(181	)	$	109,707	$	(726	)
Treasury bills	89,283		(18		)	—		—			89,283		(18		)
Asset-backed securities	48,642		(82		)	5,085		(9		)	53,727		(91		)
Sovereign bonds	22,108		(14		)	—		—			22,108		(14		)
Agency bonds	8,195		(4		)	—		—			8,195		(4		)
	$	253,434	$	(663	)	$	29,586	$	(190	)	$	283,020	$	(853	)

As of April 3, 2016, the Company did not recognize any other-than-temporary impairment of these investments. In its evaluation, management considered the type of security, the credit rating of the security, the length of time the security has been in a loss position, the size of the loss position, our intent and ability to hold the security to expected recovery of value, and other meaningful information. The Company does not intend to sell, and is unlikely to be required to sell, any of these available-for-sale investments before its effective maturity or market price recovery.

The Company recorded gross realized gains and gross realized losses on the sale of debt securities totaling $84,000 and $97,000, respectively, during the three-month period ended April 3, 2016 and $197,000 and $168,000, respectively, during the three-month period ended April 5, 2015. These gains and losses are included in "Investment income" on the Consolidated Statement of Operations. Prior to the sale of these securities, unrealized gains and losses for these debt securities, net of tax, are recorded in shareholders’ equity as other comprehensive income (loss).

The following table presents the effective maturity dates of the Company’s available-for-sale investments as of April 3, 2016 (in thousands):



	<1 year		1-2 Years		2-3 Years		3-4 Years		4-5 Years		5-7 Years		Total
Corporate bonds	$	74,627	$	77,318	$	73,926	$	4,563	$	3,414	$	—	$	233,848
Treasury bills	106,602		33,935		9,003		—		—		—		149,540
Asset-backed securities	64,478		12,311		8,608		3,286		2,594		316		91,593
Euro liquidity fund	50,094		—		—		—		—		—		50,094
Sovereign bonds	22,684		6,805		—		—		—		—		29,489
Agency bonds	980		8,195		—		—		—		—		9,175
Municipal bonds	324		4,544		—		—		—		—		4,868
	$	319,789	$	143,108	$	91,537	$	7,849	$	6,008	$	316	$	568,607

The Company is a Limited Partner in Venrock Associates III, L.P. (Venrock), a venture capital fund. The Company has committed to a total investment in the limited partnership of up to $20,500,000, with an expiration date of December 31, 2017. The Company does not have the right to withdraw from the partnership prior to this date. As of April 3, 2016, the Company contributed $19,886,000 to the partnership. The remaining commitment of $614,000 can be called by Venrock at any time before December 31, 2017. Contributions and distributions are at the discretion of Venrock’s management. No contributions were made and no distributions were received during the three-month period ended April 3, 2016.