White Mountains Insurance Group WTM Casualty-Active — Prior Year

Other product segments

Similar metrics at other companies

ACGLCasualty — Prior years

$20M+150%

SIGICasualty lines — Incurred loss and loss expense for claims occurring in the prior year

$0+100%

SIGICasualty lines — Current year

$562.1M+8.2%

EGCasualty Insurance — 2025 Prior Year Development Excluding the Impact of ADC

$118.5M—

RNRCasualty and Specialty — Net claims and claim expense ratio – prior accident years

-0.1%0.0pp

EGCasualty Insurance — Prior Year Development Net of External Reinsurance Before ADC Cessions

$232.5M—

Questions, answered.

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

White Mountains Insurance Group (WTM) reported casualty-active — prior year of $1.08M in Q4 2025.

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

White Mountains Insurance Group's casualty-active — prior year decreased by 4.4% year-over-year, from $1.13M to $1.08M.

What is the long-term trend for White Mountains Insurance Group's casualty-active — prior year?

Over 2 years (2021 to 2025), White Mountains Insurance Group's casualty-active — prior year has grown at a 7.8% compound annual growth rate (CAGR), from $3.7M to $4.3M.

What does casualty-active — prior year mean?

Represents the prior year loss development or adjustments recognized within the Casualty-Active segment. This metric reflects changes in estimates for claims occurring in previous periods, indicating the accuracy of initial underwriting and reserving assumptions.