White Mountains has reported that its investment into the Outrigger Re collateralized reinsurance sidecar, which supports its P&C insurance and reinsurance subsidiary Ark, delivered pre-tax income of $45 million in 2025, of which $55 million was attributable to the 2025 underwriting year, partially offset by a loss of $10 million from the 2024 underwriting year.Through December 31st, 2025, White Mountains reports that Outrigger Re generated pre-tax income of $55 million from the 2025 underwriting year, $29 million from the 2024 underwriting year, and $76 million from the 2023 underwriting year.For 2024, , of which $38 million was attributable to the 2024 underwriting year and $8 million to the 2023 underwriting year.For the fourth quarter of 2025, the collateralized reinsurance sidecar reported pre-tax income of $15 million, all attributable to the 2025 underwriting year, reflecting an increase on Q4’24’s pre-tax income of $6 million, of which $2 million was attributable to the 2024 underwriting year, and $4 million to the 2023 underwriting year.

After the impacts of the California wildfires in January 2025, in the first half of 2025, although the performance through the third quarter pointed to a more benign environment for major catastrophe events for the firm.In fact, White Mountains has confirmed today that catastrophe losses for the full year 2025 included $19 million of losses related to the California wildfires, net of reinstatement premiums, which is unchanged from the mid-year.Outrigger Re’s combined ratio was 41% for Q4 2025 and 57% for full year 2025, an improvement on 86% and 60%, respectively, in the prior year.

“WM Outrigger Re reported gross written premiums of $1 million and $84 million and net earned premiums of $22 million and $85 million in the fourth quarter and year ended December 31, 2025 compared to gross written premiums of $5 million and $87 million and net earned premiums of $25 million and $88 million in the fourth quarter and year ended December 31, 2024,” explains White Mountains.As we wrote previously, during the fourth quarter, , although the level of capital in the vehicle has dropped to just $70 million, as Ark adopts a new strategy of using more traditional quota share capacity.In comparison, for 2025, , $80 million of which was from third-party investors with White Mountains providing $150 million of capital..

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