Balance Sheet Components

12 Months Ended

Dec. 31, 2022

Marketable Securities

Marketable securities consisted of the following (in thousands):


December 31, 2022	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. treasuries	$	25,498	$	—	$	(479)	$	25,019
Commercial paper	24,893		—		(53)		24,840
Corporate bonds	68,845		—		(1,449)		67,396
Certificate of deposit	720		—		(14)		706
U.S. agency securities	11,295		—		(250)		11,045
	$	131,251	$	—	$	(2,245)	$	129,006


December 25, 2021	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
U.S. treasuries	$	39,128	$	—	$	(143)	$	38,985
Commercial paper	32,174		—		(13)		32,161
Corporate bonds	52,832		29		(151)		52,710
Certificate of deposit	1,200		1		(2)		1,199

	$	125,334	$	30	$	(309)	$	125,055

We typically invest in highly-rated securities with low probabilities of default. Our investment policy requires investments to be rated single A or better, limits the types of acceptable investments, concentration as to security holder and duration of the investment. The gross unrealized gains and losses in fiscal 2022 and 2021 were caused primarily by changes in interest rates.

The longer the duration of marketable securities, the more susceptible they are to changes in market interest rates and bond yields. As yields increase, those securities with a lower yield-at-cost show a mark-to-market unrealized loss. We anticipate recovering the full cost of the securities either as market conditions improve or as the securities mature. Accordingly, we believe that the unrealized losses are not as a result of a credit loss.

The contractual maturities of marketable securities were as follows (in thousands):


	December 31, 2022				December 25, 2021
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	77,663	$	76,902	$	75,804	$	75,778
Due after one year to five years	53,588		52,104		49,530		49,277
	$	131,251	$	129,006	$	125,334	$	125,055

See also Note 9, Fair Value.

Inventories, net

Inventories consisted of the following (in thousands):


	December 31, 2022		December 25, 2021
Raw materials	$	55,726	$	57,673
Work-in-progress	46,067		35,935
Finished goods	21,364		17,940
	$	123,157	$	111,548

Property, Plant and Equipment, net

Property, plant and equipment, net consisted of the following (in thousands):


	December 31, 2022		December 25, 2021
Land	$	17,136	$	4,751
Building and building improvements	44,932		41,722
Machinery and equipment	276,180		252,632
Computer equipment and software	45,813		44,667
Furniture and fixtures	7,540		7,293
Leasehold improvements	86,500		82,266
Sub-total	478,101		433,331
Less: Accumulated depreciation and amortization	(335,711)		(312,700)
Net property, plant and equipment	142,390		120,631
Construction-in-progress	47,458		25,924
Total	$	189,848	$	146,555

Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):


	December 31, 2022		December 25, 2021
Accrued compensation and benefits	$	15,864	$	29,706
Accrued income and other taxes	12,817		8,086
Accrued employee stock purchase plan contributions withheld	4,585		4,693
Accrued warranty	4,199		2,805
Accrued restructuring charges	1,249		2,478

Other accrued expenses	3,401		3,068
	$	42,115	$	50,836