Marketable Securities (Tables)

6 Months Ended

Mar. 28, 2020

The amortized cost and fair value of marketable securities as of March 28, 2020 and September 30, 2019 were as follows:



(in thousands)	March 28, 2020
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Commercial paper	$	1,482	$	—	$	—		$	1,482
Corporate notes/bonds	55,884		85		(510		)	55,459
	$	57,366	$	85	$	(510	)	$	56,941



(in thousands)	September 30, 2019
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Commercial paper	$	999	$	—	$	—		$	999
Corporate notes/bonds	56,318		146		(28		)	56,436
	$	57,317	$	146	$	(28	)	$	57,435

Unrealized Gain (Loss) on Investments

The following tables summarize the fair value and gross unrealized losses aggregated by category and the length of time that individual securities have been in a continuous unrealized loss position as of March 28, 2020 and September 30, 2019.



(in thousands)	March 28, 2020
	Less than twelve months					Greater than twelve months				Total
	Fair Value		Gross unrealized loss			Fair Value		Gross unrealized loss		Fair Value		Gross unrealized loss
Corporate notes/bonds	$	44,598	$	(510	)	$	—	$	—	$	44,598	$	(510	)



(in thousands)	September 30, 2019
	Less than twelve months					Greater than twelve months					Total
	Fair Value		Gross unrealized loss			Fair Value		Gross unrealized loss			Fair Value		Gross unrealized loss
Corporate notes/bonds	$	12,419	$	(14	)	$	16,369	$	(14	)	$	28,788	$	(28	)

Investments Classified by Contractual Maturity Date

The following table presents our marketable securities by contractual maturity date as of March 28, 2020 and September 30, 2019.



(in thousands)	March 28, 2020				September 30, 2019
	Amortized cost		Fair value		Amortized cost		Fair value
Due in one year or less	$	34,305	$	34,135	$	27,725	$	27,735
Due after one year through three years	23,061		22,806		29,592		29,700
	$	57,366	$	56,941	$	57,317	$	57,435