Marketable Securities

9 Months Ended

Jun. 27, 2020

Marketable Securities [Abstract]

Marketable Securities

9. Marketable Securities

The amortized cost and fair value of marketable securities as of June 27, 2020 and September 30, 2019 were as follows:

(in thousands)	June 27, 2020
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Commercial paper	$	1,492	$	8	$	—		$	1,500
Corporate notes/bonds		55,889		411		(12	)		56,288
	$	57,381	$	419	$	(12	)	$	57,788

(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

Our investment portfolio consists of certificates of deposit, commercial paper, corporate notes/bonds and government securities that have a maximum maturity of three years.  The longer the duration of these securities, the more susceptible they are to changes in market interest rates and bond yields.  All unrealized losses are due to changes in market interest rates, bond yields and/or credit ratings.

We review our investments to identify and evaluate investments that have an indication of possible impairment.  We concluded that, at June 27, 2020, the unrealized losses were temporary.

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 June 27, 2020 and September 30, 2019.

(in thousands)	June 27, 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	$	10,007	$	(12	)	$	—	$	—	$	10,007	$	(12	)

(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	)

The following table presents our marketable securities by contractual maturity date as of June 27, 2020 and September 30, 2019.

(in thousands)	June 27, 2020				September 30, 2019
	Amortized cost		Fair value		Amortized cost		Fair value
Due in one year or less	$	25,443	$	25,623	$	27,725	$	27,735
Due after one year through three years		31,938		32,165		29,592		29,700
	$	57,381	$	57,788	$	57,317	$	57,435