WHITE MOUNTAINS INSURANCE GROUP LTD

**UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934 (Amendment No. )

WHITE MOUNTAINS INSURANCE GROUP, LTD.

(Name of Registrant as Specified In Its Charter)

Notice of 2025

Annual General Meeting

Of Members and

Proxy Statement

LETTER FROM THE BOARD OF DIRECTORS

FROM OUR BOARD OF DIRECTORS

Dear Fellow Shareholders:

As your Board of Directors, we oversee White Mountains’s efforts to create superior growth in intrinsic value per share over long periods of time. Your Company seeks to achieve this goal by making opportunistic and value-oriented acquisitions of businesses primarily in the insurance, financial services and related sectors, operating these businesses and, if and when attractive exit valuations become available, disposing of these businesses. Since the Company’s IPO in 1985, we have delivered annualized growth in book value per share of 13% and market value per share of 12%.

2024 was an okay year for your Company. We finished 2024 with book value per share of $1,746 and adjusted book value per share of $1,834, increases of 6% and 8% for the year, respectively. Total shareholder return was 29% in 2024, compared to 25% for the S&P 500 and 35% for the S&P 500 P&C Insurance Index.

Overall, our operating businesses produced solid results in 2024. Ark had an excellent year with continued profitable growth. Kudu delivered solid results, producing a 9% return on equity and crossing the $1 billion threshold in portfolio value. Bamboo had an excellent year, with managed premiums and adjusted EBITDA up significantly. Investment returns were 6.9% for the year, well ahead of our total portfolio benchmarks.

The businesses we own today position us well for the future. As is the White Mountains “way,” we are always prospecting for new deployment opportunities, via our “platform businesses” and at the parent company.

Ongoing Dialogue with Shareholders Through Proactive Engagement

Over the last year, members of the Board and management reached out to shareholders owning 72% of White Mountains’s shares outstanding and met with all shareholders--owning 37% of shares outstanding--who accepted a meeting. In years past, feedback from these shareholder discussions has informed changes to our executive compensation program and enhanced disclosures about the skills and areas of expertise of our Board, and improvements to our ESG, risk management and human capital management practices. This year, these shareholder discussions focused primarily on our business performance and outlook, compensation philosophy and corporate governance practices. Shareholders were supportive, while also providing valuable feedback, which we have used to further enhance our proxy statement disclosures.

Our core principles served us well in 2024. It is a privilege to serve as your Board, and we value highly your support of White Mountains.

Sincerely,

The White Mountains Insurance Group Board of Directors

White Mountains Insurance Group, Ltd. (the “Company”, “Registrant” or “WTM”) is an exempted Bermuda limited liability company whose principal businesses are conducted through its subsidiaries and affiliates. Within this proxy statement, the term “White Mountains” is used to refer to one or more entities within the consolidated organization, as the context requires.

White Mountains is engaged in the business of making opportunistic and value-oriented acquisitions of businesses and assets primarily in the insurance, financial services and related sectors, operating these businesses and assets through its subsidiaries and, if and when attractive exit valuations become available, disposing of these businesses and assets.

As of December 31, 2024, White Mountains conducted its business primarily in five areas: property and casualty insurance and reinsurance, municipal bond reinsurance, capital solutions for asset and wealth management firms, property and casualty insurance distribution and other operations. White Mountains’s property and casualty insurance and reinsurance business is conducted through its subsidiary Ark Insurance Holdings Limited and its subsidiaries (collectively, “Ark”) and Outrigger Re Ltd. Segregated Account 2023-1 (“WM Outrigger Re”) (collectively with Ark, “Ark/WM Outrigger”). White Mountains’s municipal bond reinsurance business is conducted through its subsidiary HG Global Ltd. and its reinsurance subsidiary HG Re Ltd. (“HG Re”) (collectively with HG Re, “HG Global”). White Mountains provides capital solutions for asset and wealth management firms through its subsidiary Kudu Investment Management, LLC and its subsidiaries (collectively, “Kudu”). White Mountains’s property and casualty insurance distribution business is conducted through its subsidiary PM Holdings LLC (“Bamboo Holdings”) and its subsidiaries Bamboo Ide8 Insurance Services LLC (“Bamboo MGA”) and Ide8 Re Inc. (“Bamboo Captive”) (collectively with Bamboo Holdings and Bamboo MGA, “Bamboo”). White Mountains’s other operations consist of the Company and its wholly-owned subsidiary, White Mountains Capital, LLC (“WM Capital”), its other intermediate holding companies, its wholly-owned investment management subsidiary, White Mountains Advisors LLC (“WM Advisors”), investment assets managed by WM Advisors, its interests in MediaAlpha, Inc. (“MediaAlpha”), DavidShield PassportCard Ltd. and its subsidiaries (collectively, “PassportCard/DavidShield”), Elementum Holdings LP (“Elementum”), White Mountains Partners LLC (“WTM Partners”), a Bermuda special purpose collateralized reinsurance vehicle that provides reinsurance capacity to Bamboo (“Bamboo CRV”), certain other consolidated and unconsolidated entities (“Other Operating Businesses”) and certain other assets (collectively, “Other Operations”). As of December 31, 2024, White Mountains’s reportable segments were Ark/WM Outrigger, HG Global, Kudu and Bamboo with its remaining operating businesses, holding companies and other assets included in Other Operations.

The 2025 Annual General Meeting will be confined to a shareholder vote on the proposals set forth in this Proxy Statement and on such other matters properly brought before the meeting.

For a reconciliation of non-GAAP measures used in this Proxy Statement to their most comparable GAAP measures, see Annex A.