We have investments in certain debt and equity securities, which we record at fair value and primarily include in Other assets in Statement 3. Short-term and long-term investments are held with high quality institutions and, by policy, the amount of credit exposure to any one institution is limited.

We classify debt securities primarily as available-for-sale. We include the unrealized gains and losses arising from the revaluation of available-for-sale debt securities, net of applicable deferred income taxes, in equity (AOCI in Statement 3). We include the unrealized gains and losses arising from the revaluation of the equity securities in Other income (expense) in Statement 1. We generally determine realized gains and losses on sales of investments using the specific identification method for available-for-sale debt and equity securities and include them in Other income (expense) in Statement 1.

The cost basis and fair value of available-for-sale debt securities with unrealized gains and losses included in equity (AOCI in Statement 3) were as follows:


Available-for-sale debt securities	December 31, 2024						December 31, 2023
(Millions of dollars)	Cost Basis		Unrealized Pretax Net Gains (Losses)		Fair Value		Cost Basis		Unrealized Pretax Net Gains (Losses)		Fair Value
Government debt securities
U.S. treasury bonds	$	10	$	—	$	10	$	10	$	—	$	10
Other U.S. and non-U.S. government bonds	71		(3)		68		62		(2)		60

Corporate debt securities
Corporate bonds and other debt securities	3,199		(29)		3,170		3,031		(36)		2,995
Asset-backed securities	220		(1)		219		195		(3)		192

Mortgage-backed debt securities
U.S. governmental agency	476		(33)		443		433		(23)		410
Residential	2		—		2		3		(1)		2
Commercial	136		(6)		130		137		(9)		128
Total available-for-sale debt securities	$	4,114	$	(72)	$	4,042	$	3,871	$	(74)	$	3,797


Available-for-sale debt securities in an unrealized loss position:

	December 31, 2024
	Less than 12 months 1				12 months or more 1				Total
(Millions of dollars)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Government debt securities
Other U.S. and non-U.S. government bonds	$	—	$	—	$	55	$	4	$	55	$	4


Corporate debt securities
Corporate bonds	729		3		812		33		1,541		36
Asset-backed securities	7		—		37		2		44		2

Mortgage-backed debt securities
U.S. governmental agency	126		3		273		30		399		33

Commercial	13		—		113		6		126		6
Total	$	875	$	6	$	1,290	$	75	$	2,165	$	81


	December 31, 2023
	Less than 12 months 1				12 months or more 1				Total
(Millions of dollars)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Government debt securities
Other U.S. and non-U.S. government bonds	$	—	$	—	$	25	$	3	$	25	$	3

Corporate debt securities
Corporate bonds	765		—		1,011		45		1,776		45
Asset-backed securities	9		—		97		3		106		3

Mortgage-backed debt securities
U.S. governmental agency	33		—		287		25		320		25

Commercial	2		—		121		9		123		9
Total	$	809	$	—	$	1,541	$	85	$	2,350	$	85

1 Indicates the length of time that individual securities have been in a continuous unrealized loss position.

The unrealized losses on our investments in government debt securities, corporate debt securities, and mortgage-backed debt securities relate to changes in underlying interest rates and credit spreads since time of purchase. We do not intend to sell the investments, and it is not likely that we will be required to sell the investments before recovery of their respective amortized cost basis. In addition, we did not expect credit-related losses on these investments as of December 31, 2024.

The cost basis and fair value of available-for-sale debt securities at December 31, 2024, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to prepay and creditors may have the right to call obligations.



	December 31, 2024
(Millions of dollars)	Cost Basis		Fair Value
Due in one year or less	$	1,274	$	1,270
Due after one year through five years	1,820		1,794
Due after five years through ten years	304		301
Due after ten years	102		102
U.S. governmental agency mortgage-backed securities	476		443
Residential mortgage-backed securities	2		2
Commercial mortgage-backed securities	136		130
Total debt securities – available-for-sale	$	4,114	$	4,042



Sales of available-for-sale debt securities:
	Years Ended December 31,
(Millions of dollars)	2024		2023		2022
Proceeds from the sale of available-for-sale securities	$	1,223	$	940	$	767
Gross gains from the sale of available-for-sale securities	$	1	$	—	$	—
Gross losses from the sale of available-for-sale securities	$	5	$	1	$	5

In addition, we had $1,900 million of investments in time deposits classified as held-to-maturity debt securities as of December 31, 2023. We did not have any investments classified as held-to-maturity debt securities as of December 31, 2024. These investments matured within one year and were included in Prepaid expenses and other current assets in Statement 3. We record held-to-maturity debt securities at amortized cost, which approximates fair value.

For the years ended December 31, 2024 and 2023, the net unrealized gains (losses) for equity securities held at December 31, 2024 and 2023 were $25 million and $(12) million, respectively.