Following is a summary of debt securities as of April 1, 2023 and December 31, 2022:


	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(Amounts are in millions)
April 1, 2023
Taxable bonds	$	9,931		10		703	9,238
Tax exempt bonds	30			—		—	30
Restricted investments	187			—		4	183
	$	10,148		10		707	9,451
December 31, 2022
Taxable bonds	$	9,705		6		830	8,881
Tax exempt bonds	37			—		—	37
Restricted investments	170			—		4	166
	$	9,912		6		834	9,084

The Company maintains restricted investments primarily for the benefit of the Company’s insurance carrier related to self-insurance reserves. These investments are held as collateral and not used for claim payments.

Following is a summary of the cost and fair value of debt securities by expected maturity as of April 1, 2023 and December 31, 2022:


	April 1, 2023				December 31, 2022
	Cost		Fair Value		Cost		Fair Value
	(Amounts are in millions)
Due in one year or less	$	758		751		570	566
Due after one year through five years	8,681			8,064		8,355	7,661
Due after five years through ten years	707			634		985	855
Due after ten years	2			2		2	2
	$	10,148		9,451		9,912	9,084

The Company had no debt securities with credit losses as of April 1, 2023 and December 31, 2022.

Following is a summary of debt securities with other unrealized losses by the time period impaired as of April 1, 2023 and December 31, 2022:


	Less Than 12 Months				12 Months or Longer			Total
	Fair Value		Unrealized Losses		Fair Value	Unrealized Losses		Fair Value	Unrealized Losses
	(Amounts are in millions)
April 1, 2023
Taxable bonds	$	1,303		15	7,223		688	8,526		703

Restricted investments	168			2	15		2	183		4
	$	1,471		17	7,238		690	8,709		707
December 31, 2022

Taxable bonds	$	3,705		199	4,627		631	8,332		830
Restricted investments	151			2	15		2	166		4
	$	3,856		201	4,642		633	8,498		834

There are 448 debt securities contributing to the total unrealized losses of $707 million as of April 1, 2023. Unrealized losses related to debt securities are primarily due to increases in interest rates that occurred since the debt securities were purchased. The Company continues to receive scheduled principal and interest payments on these debt securities.

Equity securities are measured at fair value with net unrealized gains and losses from changes in the fair value recognized in earnings (fair value adjustment). The fair value of equity securities was $2.7 billion and $2.5 billion as of April 1, 2023 and December 31, 2022, respectively.

Net realized gain or loss on investments represents the difference between the cost and the proceeds from the sale of debt and equity securities. The net realized gain or loss on investments excludes the net gain or loss on the sale of equity securities previously recognized through the fair value adjustment, which is presented separately in the following table.

Following is a summary of investment income (loss) for the three months ended April 1, 2023 and March 26, 2022:


		Three Months Ended
	April 1, 2023			March 26, 2022
	(Amounts are in millions)
Interest and dividend income		$	82		57
Net realized gain on investments		—			1
		82			58
Fair value adjustment, due to net unrealized gain (loss), on equity securities held at end of period		246			(581)

		$	328		(523)