White Mountains Insurance Group reported higher book value and improved results across its core businesses during the second quarter of 2025, as stronger underwriting margins and investment income helped offset volatility in its equity holdings.
As of June 30, book value per share reached $1,804, marking a 3% gain for both the quarter and the first half of the year, inclusive of dividends. The group recorded $124 million in comprehensive income attributable to common shareholders for the quarter, compared to a $55 million loss in the same period last year.
Underwriting performance at Ark/WM Outrigger strengthened, with the segment posting a combined ratio of 84%, down from 87% in Q2 2024. Gross written premiums rose to $815 million in the quarter, up from $697 million, while first-half premiums increased to $1.9 billion from $1.6 billion. Pre-tax income for the segment rose to $91 million, supported by $51 million in investment gains.
Kudu Investment Management contributed $20 million in revenue and $11 million in pre-tax income during the quarter. Adjusted EBITDA came in at $16 million.
White Mountains’ “other operations” swung to a $36 million pre-tax profit, reversing a $153 million loss a year earlier. The improvement was driven largely by a $31 million unrealized gain on the company’s investment in MediaAlpha, compared to a $139 million loss in the same period last year. Excluding MediaAlpha, realized and unrealized investment gains totaled $32 million, up from $9 million.
Revenue from other operations grew to $57 million from $15 million, while cost of sales rose to $42 million from $7 million, largely due to the acquisition of Enterprise Solutions. General and administrative expenses also climbed to $54 million, reflecting transaction-related costs and expenses tied to the new acquisition.
The company’s total investment portfolio delivered a 2.7% return for the quarter, or 2.3% excluding MediaAlpha, up from a slight loss in the same period last year. Year-to-date, the portfolio returned 4.5%, with gains driven by both public and private equity positions.
White Mountains said results for the quarter reflected a combination of sound underwriting, disciplined growth, and positive contributions from its investment holdings, although equity market swings remain a source of earnings volatility.
