White Mountains Insurance Group (WTM) Q3 2025 earnings summary

Executive summary

• Book value per share rose 3% in Q3 2025 and 6% year-to-date, reaching $1,851, with a projected increase to $2,176 after the Bamboo sale closes in Q4 2025.

• Comprehensive income attributable to common shareholders was $114 million for Q3 2025 and $272 million for the first nine months, down from $180 million and $361 million in the prior year periods.

• Strong operating results and investment returns were reported across core segments, with notable growth in Ark, HG Global, Kudu, and Bamboo.

• The sale of a 77% stake in Bamboo to CVC Capital Partners is expected to add $325 per share to book value and increase undeployed capital to $1.1 billion.

Financial highlights

• Total revenues for Q3 2025 were $864 million, up from $839 million in Q3 2024; nine-month revenues were $2.13 billion, up from $1.88 billion year-over-year.

• Net income attributable to common shareholders was $114 million for Q3 2025 and $271 million for the first nine months, compared to $179 million and $361 million in the prior year.

• Basic EPS was $44.18 for Q3 2025 and $105.18 for the first nine months, versus $69.68 and $140.66 in the prior year.

• Book value per share as of September 30, 2025, was $1,851, up from $1,746 at year-end 2024.

• Total consolidated portfolio return was 2.1% in Q3 2025 (2.0% excluding MediaAlpha), and 6.6% for the first nine months (6.8% excluding MediaAlpha).

Outlook and guidance

• The Bamboo transaction is expected to close in Q4 2025, significantly boosting book value per share and liquidity.

• Management anticipates continued profitable growth in Bamboo and Distinguished, with expansion into new markets and product lines.