WHITE MOUNTAINS INSURANCE GROUP LTD

White Mountains’s investment philosophy is to maximize long-term, after-tax total returns while taking prudent levels of risk and maintaining a diversified portfolio, subject to White Mountains’s investment guidelines and various regulatory restrictions. Under White Mountains’s investment philosophy, each dollar of after-tax investment income or investment gains (realized or unrealized) is valued equally. White Mountains’s investment philosophy also incorporates Environmental, Social and Governance (“ESG”) considerations. For investment assets actively managed by WM Advisors, thorough credit risk assessments are conducted, utilizing Nationally-Recognized Statistical Rating Organizations research and ratings. For actively managed investment assets sub-advised to third-party registered investment managers, White Mountains only utilizes managers who incorporate ESG factors into their investment processes.

White Mountains maintains a fixed income portfolio that consists primarily of high-quality, short-duration, fixed maturity investments and short-term investments. White Mountains invests in fixed maturity investments that are attractively priced in relation to their investment risks and actively manages the average duration of the fixed income portfolio. As of December 31, 2024, the fixed income portfolio duration, including short-term investments, was 1.9 years. White Mountains has established relationships with select third-party registered investment advisers to manage a portion of its fixed income portfolio. See “Portfolio Composition” on page 71.

White Mountains maintains an equity portfolio that consists of common equity securities, its investment in MediaAlpha and other long-term investments. As of December 31, 2024, White Mountains’s portfolio of common equity securities consists of international listed equity funds and passive exchange traded funds (“ETFs”). White Mountains’s other long-term investments consist primarily of unconsolidated entities, Kudu’s Participation Contracts, private equity funds and hedge funds, a bank loan fund, Lloyd’s trust deposits, ILS funds and private debt instruments.