White Mountains Insurance Group Ltd (WTM) · Nov 5, 2026 · Earnings

White Mountains earnings show solid operations but book value slips

In line — Book value per share -1% in Q3; Ark combined ratio 75%

White Mountains earnings show Ark, Distinguished and WTM Partners gaining traction, but higher rates and MediaAlpha losses pushed book value lower.

White Mountains is building a diversified insurance-and-investment platform around Ark, Kudu, HG Global, Distinguished and the newer WTM Partners businesses, while keeping substantial capital available for further deployment. The quarter says that operating execution is holding up, but the investment portfolio remains the swing factor.

The underlying businesses were mostly healthy, but not enough to overcome investment marks. Ark improved its combined ratio to 75% from 76% and grew quarterly gross written premiums to $386 million, while WTM Partners moved from a loss to positive adjusted EBITDA. Distinguished also expanded its managed-premium and adjusted-EBITDA base. Those are real signs that the operating platform is progressing, but they were offset by higher-rate losses at Kudu and HG Global and a sharp decline in MediaAlpha.

MetricQ3 2026Q3 2025Key comparison
Book value per share (Financial Highlights)$2,242.76 (-0.7%)$1,851.33—
Comprehensive income attributable to common shareholders (Income Statement)$(39)M$114M—
Ark combined ratio (Ark results)75.4%72.9%—
WTM Partners adjusted EBITDA (Segment results)$8.8M$2.2M—
MediaAlpha unrealized loss (Other Operations)$(53.6)M$7.7M gain—

Ark remains the clearest operating bright spot. Its 75% combined ratio was slightly better than the prior-year reported ratio on a comparable consolidated basis, despite $10 million of war-related losses, and tangible book value grew 5% during the quarter. The caveat is that year-to-date gross written premiums declined as property-market conditions softened, so the improvement is more about underwriting quality than broad-based volume growth. 〔0〕

The quarter exposed White Mountains’ sensitivity to interest rates and market marks. Kudu’s adjusted EBITDA rose to $18 million, but its trailing twelve-month return on equity fell to 8% from 15% as higher discount rates reduced portfolio values. HG Global also produced record quarterly premiums, yet its investment portfolio and BAM surplus notes lost value. This makes the reported earnings weaker than the operating businesses alone would suggest. 〔1〕

The MediaAlpha sale reduces future concentration, but does not erase the quarter’s damage. White Mountains agreed to sell 5.5 million shares for $13.90 each, cutting its ownership from 29% to 21%. That is a meaningful reduction in exposure after a $54 million quarterly mark-to-market loss, but the remaining stake can still move book value materially: the filing says each $1 change in MediaAlpha’s share price would affect White Mountains’s book value per share by about $5.

The business mix is improving, but the consolidated scorecard is still investment-sensitive. WTM Partners’ adjusted EBITDA more than tripled year over year to $9 million, and Distinguished’s trailing twelve-month ScaleCo adjusted EBITDA reached $30 million. However, consolidated book value per share fell 1% in the quarter and comprehensive income attributable to common shareholders was negative, showing that the newer operating platforms have not yet become large enough to neutralize portfolio volatility.

Bottom line: This was an operationally solid but financially mixed quarter. The insurance and specialty platforms advanced, yet rate-driven marks and MediaAlpha losses kept the headline result roughly in line rather than turning it into a clear positive surprise.

What to watch next

Form 10-Q filing, November 5

Original filing on SEC EDGAR

More White Mountains Insurance Group Ltd news

White Mountains earnings show solid operations but book value slips | WTM Stock News
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