NOTE 4:-

MARKETABLE SECURITIES

Marketable securities with contractual maturities of up to one year are as follows:


	December 31,
	2018					2017
	Amortized cost	Gross unrealized gains		Gross unrealized losses	Fair value	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value

Government and corporate debentures - fixed interest rate	$1,203,258	$	9	$(5,017)	$1,198,249	$	1,026,555	$	48	$	(1,698	)	$	1,024,905
Government-sponsored enterprises debentures	231,699		6	(1,200)	230,505		112,951		1		(275	)		112,677
Government and corporate debentures - floating interest rate	13,902		-	(15)	13,887		27,681		14		(11	)		27,684


	$1,448,859	$	15	$(6,232)	$1,442,642	$	1,167,187	$	63	$	(1,984	)	$	1,165,266

Marketable securities with contractual maturities of over one year through five years are as follows:


	December 31,
	2018									2017
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value		Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value

Government and corporate debentures - fixed interest rate		$1,819,541		$1,089		$(21,630)			$1,799,001	$	1,985,849	$	384	$	(15,204	)	$	1,971,029
Government-sponsored enterprises debentures		383,190		278		(4,092	)		379,376		424,619		-		(4,687	)		419,932
Government and corporate debentures - floating interest rate		109,878		1		(910	)		108,969		46,247		134		(27	)		46,354


	$	2,312,609	$	1,368	$	(26,632	)	$	2,287,345	$	2,456,715	$	518	$	(19,918	)	$	2,437,315

Investments with continuous unrealized losses for less than 12 months and 12 months or greater and their related fair values were as follows:


	December 31, 2018
	Less than 12 months					12 months or greater					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Government and corporate debentures - fixed interest rate	$	807,274	$	(4,369	)	$	1,852,625	$	(22,278	)	$	2,659,899	$	(26,647	)
Government-sponsored enterprises debentures		40,213		(79	)		429,101		(5,213	)		469,315		(5,292	)
Government and corporate debentures - floating interest rate		115,511		(917	)		5,380		(7	)		120,892		(925	)


	$	962,999	$	(5,366	)	$	2,287,106	$	(27,498	)	$	3,250,06	$	(32,864	)


	December 31, 2017
	Less than 12 months					12 months or greater					Total
	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
Government and corporate debentures - fixed interest rate	$	1,647,125	$	(7,318	)	$	1,063,690	$	(9,585	)	$	2,710,815	$	(16,903	)
Government-sponsored enterprises debentures		236,403		(1,281	)		294,986		(3,681	)		531,389		(4,962	)
Government and corporate debentures - floating interest rate		27,810		(37	)		-		-			27,810		(37	)


	$	1,911,338	$	(8,636	)	$	1,358,676	$	(13,266	)	$	3,270,014	$	(21,902	)

As of December 31, 2018 and 2017, interest receivable amounted to $ 22,940 and $ 19,871, respectively, and is included within prepaid expenses and other current assets in the balance sheets.