White Mountains Insurance Group (NYSE:WTM) reported strong book value growth for the fourth quarter and full year ended December 31, 2025, fueled by the Bamboo sale and solid operating performance across its investment and insurance operations.
Book value per share reached $2,188 as of December 31, 2025, increasing 18% in the fourth quarter and 25% for the full year including dividends.
The Bamboo sale materially contributed, adding roughly $320 to BVPS in 2025.
Comprehensive income totaled $837 million in the fourth quarter and $1,109 million for the year.
The company also repurchased approximately $190 million of its common shares during the fourth quarter.
Meanwhile, White Mountains ended the year with roughly $1 billion of undeployed capital, including a distribution received from WM Outrigger in January 2026.
Other notable items included Ark’s gross written premiums of $2.6 billion, up 16% year-over-year, Kudu achieving a 13% return on equity for 2025, and a $73 million deferred tax expense reversal in the fourth quarter related to the Bermuda economic transition adjustment.