White Mountains Insurance Group announced results for the third quarter and first nine months of 2026. The figures detailed here show growth in Ark’s book value and tangible book value, alongside operating measures the company uses for several other businesses and investment portfolios.
- Ark’s tangible book value reached $1.82 billion at Sept. 30, up from $1.74 billion at June 30 and $1.67 billion at year-end 2025. Ark’s GAAP book value was $1.67 billion at Sept. 30, compared with $1.62 billion at June 30 and $1.59 billion at the end of 2025.
- Including dividends, Ark’s tangible book value grew 5.1% in the third quarter and 12.0% year to date. The comparable growth rates for GAAP book value were 3.6% and 8.1%. Ark had declared $50.5 million in dividends year to date.
- The tangible-book-value calculation differs from GAAP book value. It removes goodwill and other intangible assets, while adding the estimated value of potential additional shares that Ark management rollover shareholders could earn if White Mountains meets specified investment-return thresholds. That potential share award affects how Ark’s economics could be allocated among shareholders, but not Ark’s standalone GAAP or tangible book value.
- The results announcement also uses non-GAAP measures for other businesses. These include EBITDA and adjusted EBITDA for Kudu, Distinguished’s ScaleCo and WTM Partners, as well as Kudu revenue and cash-yield measures. White Mountains also presents portfolio-return measures excluding MediaAlpha. The measures are reconciled to comparable GAAP figures.
The Ark figures show that tangible book value grew faster than GAAP book value in both the quarter and year to date. The growth rates include dividends, so they reflect both changes in book value and distributions to shareholders.