White Mountains Insurance Group, Ltd. is an exempted Bermuda limited liability company that focuses on making opportunistic and value oriented acquisitions of businesses and assets in the insurance financial services and related sectors. The company operates these businesses through its subsidiaries and disposes of them when attractive exit valuations become available. As of December 31 2025 its primary activities included property and casualty insurance and reinsurance municipal bond guarantee reinsurance capital solutions for asset and wealth management firms specialty insurance distribution and other operations.

White Mountains Insurance Group, Ltd. generates revenue primarily through earned premiums investment income and net realized and unrealized investment gains from its insurance and reinsurance subsidiaries. The company also earns fee revenues profit commissions and management fees from its capital solutions and specialty distribution businesses. Additionally it receives interest payments and distributions from its municipal bond guarantee reinsurance and other investment holdings.

The company operates through the following segments: Ark/WM Outrigger HG Global Kudu and Distinguished.

• The Ark/WM Outrigger segment provides property and casualty insurance and reinsurance through its subsidiaries Ark and WM Outrigger Re offering niche lines such as property specialty marine & energy casualty and accident & health.

• The HG Global segment provides municipal bond guarantee reinsurance through its subsidiary HG Re which offers first loss protection up to 15 percent of par outstanding for each policy assumed from Build America Mutual Assurance Company.

• The Kudu segment supplies capital solutions for boutique asset and wealth management firms structuring investments as noncontrolling equity interests that generate immediate cash yields and support generational ownership transfers management buyouts acquisition growth and legacy partner liquidity.

• The Distinguished segment operates as a full service MGA and program administrator for specialty property and casualty insurance placing insurance across programs grouped into ScaleCo and GrowthCo verticals earning commissions based on volume and profitability of the insurance it places.

White Mountains Insurance Group, Ltd. maintains a focused presence in specialty insurance and reinsurance competing with Lloyd's syndicates London market participants and Bermuda based insurers such as Arch Capital Group Ltd. and RenaissanceRe Holdings Ltd. In the municipal bond guarantee reinsurance arena HG Global faces competition primarily from Assured Guaranty Ltd. The company's capital solutions business Kudu serves boutique asset and wealth management firms alongside peers that provide similar private equity style financing. Distinguished operates in the highly competitive specialty insurance distribution market where rivals are differentiated by price service quality and technology.

The company serves a diverse customer base that includes insurance and reinsurance intermediaries such as Marsh & McLennan Companies Inc. Arthur J. Gallagher & Co Aon plc Howden Insurance Group and Willis Towers Watson plc municipal bond issuers like the Metropolitan Transportation Authority the City of Sherman TX the New Jersey Transportation Trust Fund Authority and the City of Chicago IL as well as boutique asset and wealth management firms and specialty insurance distribution partners.