SCHEDULE: MediaAlpha Ownership Update: White Mountains Stake at 31.7%

White Mountains Insurance Group and WM Hinson updated their beneficial ownership in MediaAlpha, Inc. Class A Common Stock to 31.7%, a change solely due to an increase in outstanding shares.

Summary

• White Mountains Insurance Group, Ltd. and WM Hinson (Bermuda) Ltd. (Reporting Persons) filed Amendment No. 5 to their Schedule 13D regarding MediaAlpha, Inc. Class A Common Stock.
• The amendment reports a change in the percentage of Class A Shares beneficially owned by the Reporting Persons.
• This change is solely attributed to an increase in the number of outstanding Class A Shares, as disclosed in MediaAlpha's Form 10-Q filed on August 6, 2025.
• As of the filing date, the Reporting Persons collectively beneficially own 17,856,614 Class A Shares.
• This aggregate ownership represents approximately 31.68% of the outstanding Class A Shares.
• White Mountains directly holds 900,000 Class A Shares and indirectly owns 16,956,614 Class A Shares through its wholly-owned subsidiary, WM Hinson.
• The percentage calculations are based on 56,370,303 Class A Shares issued and outstanding as of July 31, 2025.

Sentiment

Score: 5

Explanation: The filing is a routine amendment to report a change in beneficial ownership percentage, explicitly stating it's due to a change in outstanding shares, not a strategic move or performance issue. It's neutral in sentiment.

Risks

• Reporting Persons disclaim beneficial ownership of Class A Shares that they may be deemed to beneficially own, particularly those held by WM Hinson or other Stockholders' Agreement Parties.
• The filing of this amendment does not constitute an admission that any Reporting Person, or their partners, members, directors, officers, or affiliates, is the beneficial owner of any Class A Shares they may be deemed to beneficially own.
• Reporting Persons disclaim membership in a group with each other Stockholders' Agreement Party, despite potential deeming of beneficial ownership due to the Stockholders Agreement.

Related Party Transactions

• OBF Investments, LLC, which holds 3,923,885 Class B Shares, is owned by trusts for the benefit of Steven Yi and members of his family. Mr. Yi does not have voting or dispositive control over these shares.

Key Dates

Keywords

MediaAlpha, White Mountains Insurance Group, WM Hinson, Schedule 13D, Beneficial Ownership, Class A Common Stock, SEC Filing, Investment, Shareholding, Corporate Governance