RESERVE FOR LOSSES AND LOSS EXPENSES

3 Months Ended

Mar. 31, 2025

Reserve Roll-Forward

The following table presents a reconciliation of the Company's beginning and ending gross reserve for losses and loss expenses and net reserve for unpaid losses and loss expenses:


	Three months ended March 31,
	2025		2024

Gross reserve for losses and loss expenses, beginning of period	$	17,218,929	$	16,434,018
Less reinsurance recoverable on unpaid losses and loss expenses, beginning of period	(6,840,897)		(6,323,083)
Net reserve for unpaid losses and loss expenses, beginning of period	10,378,032		10,110,935

Net incurred losses and loss expenses related to:
Current year	803,862		728,671
Prior years	(17,937)		—
	785,925		728,671

Net paid losses and loss expenses related to:
Current year	(45,288)		(50,724)
Prior years	(723,513)		(612,571)
	(768,801)		(663,295)

Foreign exchange and other	149,785		(48,602)

Net reserve for unpaid losses and loss expenses, end of period	10,544,941		10,127,709
Reinsurance recoverable on unpaid losses and loss expenses, end of period	6,944,518		6,503,188
Gross reserve for losses and loss expenses, end of period	$	17,489,459	$	16,630,897

Estimates for Significant Catastrophe Events

At March 31, 2025, net reserves for losses and loss expenses included estimated amounts for numerous catastrophe events. The magnitude and complexity of losses arising from certain of these events inherently increase the level of uncertainty and, therefore, the level of management judgment involved in arriving at estimated net reserves for losses and loss expenses. These events include California Wildfires in 2025, Hurricane Milton and Hurricane Helene in 2024. As a result, actual losses for these events may ultimately differ materially from current estimates. During the three months ended March 31, 2025, the Company recognized catastrophe and weather-related losses, net of reinsurance, of $49 million (2024: $20 million).

Prior Year Reserve Development

The Company's net favorable (adverse) prior year reserve development arises from changes to estimates of losses and loss expenses related to loss events that occurred in previous calendar years. The following table presents net favorable (adverse) prior year reserve development by segment:


	Three months ended March 31,
	2025		2024
	Favorable (Adverse)		Favorable (Adverse)

Insurance	$	13,978	$	—
Reinsurance	3,959		—
Total	$	17,937	$	—

The following sections provide further details on net favorable (adverse) prior year reserve development by segment, reserve class and accident year:

Insurance Segment:

The following table maps the Company's lines of business to reserve classes:


Insurance segment
	Reserve class
	Property	Casualty	Specialty other
Reported lines of business
Property	X
Professional lines		X
Liability		X
Cyber		X
Marine and aviation			X
Accident and health			X
Credit and political risk			X

Prior year reserve development by reserve class was as follows:


	Three months ended March 31,
	2025		2024
	Favorable (Adverse)		Favorable (Adverse)

Property	$	9,996	$	8,011
Casualty	—		—
Specialty other	3,982		(8,011)
Total	$	13,978	$	—

2025

For the three months ended March 31, 2025, net favorable prior year reserve development of $14 million was recognized, the principal component of which was:

•$10 million of net favorable prior year reserve development on property business primarily due to better than expected loss emergence mainly related to the 2023 accident year.

2024

For the three months ended March 31, 2024, net prior year reserve development of $nil was recognized, the principal components of which were:

•$8 million of net favorable prior year reserve development on property business primarily due to better than expected loss emergence mainly related to the 2021 and 2022 accident years.

•$8 million of net adverse prior year reserve development on the specialty other reserve class primarily associated with an increase in the loss estimate attributable to a specific large claim in the marine and aviation line of business related to the 2019 accident year.

Reinsurance Segment:

The following table maps the Company's lines of business to reserve classes:


Reinsurance segment
	Reserve class
	Casualty	Specialty	Run-off
Reported lines of business
Liability	X
Professional lines	X
Motor	X
Accident and health		X
Credit and surety		X
Agriculture		X
Marine and aviation		X
Catastrophe			X
Property			X
Engineering			X

Prior year reserve development by reserve class was as follows:


	Three months ended March 31,
	2025		2024
	Favorable (Adverse)		Favorable (Adverse)

Casualty	$	—	$	—
Specialty	3,834		—
Run-off	125		—
Total	$	3,959	$	—

2025

For the three months ended March 31, 2025, net favorable prior year reserve development of $4 million was recognized.

2024

For the three months ended March 31, 2024, net prior year reserve development of $nil was recognized.