What is White Mountains Insurance Group's casualty-active — 6?

White Mountains Insurance Group (WTM) reported casualty-active — 6 of 11.2% in Q4 2025.

How has White Mountains Insurance Group's casualty-active — 6 changed year-over-year?

White Mountains Insurance Group's casualty-active — 6 decreased by 4.3% year-over-year, from 11.7% to 11.2%.

What does casualty-active — 6 mean?

Quantifies the adjustment to prior year loss and loss adjustment expense reserves within the Casualty-Active segment. It provides transparency into how historical underwriting assumptions align with actual claims settlement patterns.

White Mountains Insurance Group (WTM) Casualty-Active — 6

Screener

Other product segments

Casualty-Runoff

6.7%-1.5%

Marine & Energy

6.5%-5.8%

Specialty

2.5%0.0%

Property and Accident & Health

1.9%+46.2%

Similar metrics at other companies

HIPOCasualty Lines — 6

0%—

HGBermuda - Casualty — 6

11%0.0pp

HGInternational - Casualty — 6

7%-1.0pp

FRHCCivil Liability — 6

6%+4.1pp

FRHCLife Insurance — 6

0%—

FRHCMotor Vehicle — 6

0%—

Other financials

Income statement

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Revenue$844.6M+22.5%

Gross profit$764.5M+18.2%

Net income$199.5M+62.3%

Balance sheet

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Total debt$932.5M+34.2%

Total equity$5.4B+16.0%

Total assets$13.8B+16.4%

Cash flow

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Operating cash flow-$55.5M-131%

Valuation

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Market cap$5.3B+15.6%

P/E4.7×—

P/S1.4×-0.5×

Profitability

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Gross margin94.1%-3.2pp

Net margin29.3%—

Returns & leverage

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Return on equity22.4%—

Debt / equity0.2×0.0×

Where this comes from

Reported directly by White Mountains Insurance Group in its filing.

Tagged under the XBRL concept us-gaap:ShortdurationInsuranceContractsHistoricalClaimsDurationYearSix.

The source filing: White Mountains Insurance Group’s 10-K, filed February 27, 2026.

Filed: Feb 27, 2026, 9:21 AM EST
Fiscal year: FY2025
Accession: 0001628280-26-012603

Casualty-Active	Casualty-Active / Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Casualty-Active / Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Casualty-Active / Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Casualty-Active / Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance	Average Annual Percentage Payout of Incurred Loss and LAE by Age, Net of Reinsurance
Years	1	2	3	4	5	6	7	8	9	10
	3.8%	7.5%	11.4%	12.9%	10.0%	11.2%	7.2%	5.1%	4.2%	3.4%

Item 16. Form 10-K Summary.

FAQ

What is White Mountains Insurance Group's casualty-active — 6?: White Mountains Insurance Group (WTM) reported casualty-active — 6 of 11.2% in Q4 2025.
How has White Mountains Insurance Group's casualty-active — 6 changed year-over-year?: White Mountains Insurance Group's casualty-active — 6 decreased by 4.3% year-over-year, from 11.7% to 11.2%.
What does casualty-active — 6 mean?: Quantifies the adjustment to prior year loss and loss adjustment expense reserves within the Casualty-Active segment. It provides transparency into how historical underwriting assumptions align with actual claims settlement patterns.