Substantially all of our non-current investment securities are held within our run-off insurance operations and are classified as non-current as they support the long-duration insurance liabilities and include debt securities all classified as available-for-sale, substantially all of which are investment-grade.


	March 31, 2025								December 31, 2024
	Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair value		Amortized cost		Gross unrealized gains		Gross unrealized losses		Estimated fair value




Debt
U.S. corporate	$	28,222	$	662	$	(2,206)	$	26,678	$	28,456	$	546	$	(2,309)	$	26,692
Non-U.S. corporate	2,920		28		(285)		2,663		2,970		23		(302)		2,691
State and municipal	2,356		38		(203)		2,192		2,409		22		(235)		2,196
Mortgage and asset-backed	5,258		70		(157)		5,172		5,007		47		(183)		4,870
Government and agencies	1,178		6		(108)		1,075		1,180		4		(118)		1,066
Other equity	229		—		—		229		225		—		—		225
Non-current investment securities	$	40,163	$	804	$	(2,958)	$	38,010	$	40,248	$	641	$	(3,148)	$	37,741

The estimated fair value of investment securities at March 31, 2025 increased since December 31, 2024, primarily due to lower market yields partially offset by net proceeds from debt/equity securities sales and early redemptions, both from our run-off insurance operations.

Total estimated fair value of debt securities in an unrealized loss position were $20,859 million and $21,876 million, of which $13,913 million and $14,011 million had gross unrealized losses of $(2,663) million and $(2,795) million and had been in a loss position for 12 months or more at March 31, 2025 and December 31, 2024, respectively. Gross unrealized losses at March 31, 2025 included $(96) million related to commercial mortgage-backed securities (CMBS) collateralized by pools of commercial mortgage loans on real estate, and $(57) million related to asset-backed securities. The majority of our CMBS and asset-backed securities in an unrealized loss position have received investment-grade credit ratings from the major rating agencies. The majority of our U.S. and non-U.S. corporate securities' gross unrealized losses were in the consumer, electric, technology and communication industries. For our securities in an unrealized loss position, the losses are not indicative of credit losses, we currently do not intend to sell the investments, and it is not more likely than not that we will be required to sell the investments before recovery of their amortized cost basis.


	Three months ended March 31
		2025		2024
Net unrealized gains (losses) for equity securities with readily determinable fair value (RDFV)		$	5	$	441
Proceeds from debt/equity securities sales and early redemptions		672		3,196
Gross realized gains on debt securities		5		8
Gross realized losses on debt securities		(7)		(11)

The majority of our non-current investment securities are classified within Level 2, as their valuation is determined based on significant observable inputs. Investments with a fair value of $4,351 million and $5,074 million, including the AerCap senior note, are classified within Level 3, as significant inputs to their valuation models are unobservable at March 31, 2025 and December 31, 2024, respectively. During the three months ended March 31, 2025, $949 million was transferred out of Level 3 related to increases in the observability of external information used in determining fair value in our run-off insurance operations and primarily included certain investments in private placement U.S. and non-U.S. corporate debt securities. During the three months ended March 31, 2025 there were no significant transfers into Level 3 and during three months ended March 31, 2024, there were no significant transfers into or out of Level 3.

In addition to the equity securities described above, we held $1,491 million and $1,439 million of equity securities without RDFV including $1,462 million and $1,410 million within our run-off insurance operations at March 31, 2025 and December 31, 2024, respectively, that are classified within All other assets in our Statement of Financial Position. Fair value adjustments, including impairments, recorded in income were $38 million and $34 million for the three months ended March 31, 2025 and 2024, respectively. These are primarily limited partnership investments in private equity, infrastructure and real estate funds that are measured at net asset value per share (or equivalent) as a practical expedient to estimated fair value and are excluded from the fair value hierarchy. These limited partnership investments are generally not eligible for redemption and generally cannot be sold without approval of the general partner. Distributions from each fund will be received as the underlying investments of the funds are liquidated at the discretion of the general partner. These investments are generally considered illiquid and our ability to receive the most recent net asset value in a sale would be determined by external market factors.