SCHEDULE: Clarkston Group Discloses 3.21% Stake in Affiliated Managers Group

Clarkston Capital Partners and its affiliates have reported a 3.21% beneficial ownership stake in Affiliated Managers Group, Inc., totaling 904,119 shares.

Summary

• Clarkston Capital Partners, LLC, along with Clarkston Companies, Inc., Modell Capital LLC, Jeffrey A. Hakala, Gerald W. Hakala, and Jeremy J. Modell, collectively reported beneficial ownership of 904,119 shares of Affiliated Managers Group, Inc. Common Stock.
• This represents 3.21% of the outstanding Common Stock, based on 28,128,908 shares outstanding as of November 4, 2025, as reported in the Issuer's quarterly report on Form 10-Q filed on November 6, 2025.
• The reporting persons hold 452,500 shares with sole voting power and 394,049 shares with shared voting power.
• They also hold 452,500 shares with sole dispositive power and 451,619 shares with shared dispositive power.
• The securities were acquired and are held in the ordinary course of business, not for the purpose of changing or influencing control of the issuer.

Sentiment

Score: 7

Explanation: StockSavvy.ai views this as a moderately positive signal, indicating a stable, non-activist institutional investment in Affiliated Managers Group, Inc., suggesting long-term confidence from the reporting group.

Positives

• A significant, stable ownership stake by an investment adviser and related entities suggests confidence in the issuer's long-term prospects.
• The filing indicates the shares are held in the ordinary course of business, not for activist purposes, implying a passive, supportive investment.

Negatives

• No specific negatives are disclosed in this beneficial ownership report.

Risks

• No specific risks related to the issuer's operations or financial health are disclosed in this beneficial ownership report. The inherent risks of equity investment apply.

Future Outlook

This filing, a Schedule 13G/A, is a disclosure of beneficial ownership and does not contain forward-looking statements or guidance regarding the issuer's future performance or strategic direction.

Management Comments

• The securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities.

Industry Context

StockSavvy.ai notes that a 3.21% stake by an investment adviser group like Clarkston Capital Partners in a diversified asset management company such as Affiliated Managers Group, Inc. is a notable, albeit non-activist, institutional investment. This type of filing reflects ongoing portfolio management and confidence in the asset management sector, which continues to navigate evolving market conditions and client demands.

Comparison to Industry Standards

• This filing is a standard disclosure of beneficial ownership and does not provide performance metrics for comparison to industry standards. It simply reports the ownership stake of a specific group in Affiliated Managers Group, Inc.

Stakeholder Impact

• Shareholders: The disclosure of a significant, stable institutional ownership stake may provide a degree of confidence to other shareholders, indicating a long-term investment perspective from the reporting group.
• Management: The non-activist nature of the filing suggests that the reporting group is not seeking to influence control, allowing management to continue executing its strategy without immediate pressure from this specific shareholder group.

Next Steps

• Subsequent amendments to this Schedule 13G will be filed on behalf of each undersigned without the necessity of filing additional joint filing agreements.
• Each undersigned will be responsible for the timely filing of such amendments and for the completeness and accuracy of their own information.

Key Dates

Recommendation

This Schedule 13G/A filing primarily discloses a beneficial ownership stake by Clarkston Capital Partners and its affiliates in Affiliated Managers Group, Inc. at 3.21%. The filing explicitly states the shares were acquired and are held in the ordinary course of business, not for the purpose of changing or influencing control. This indicates a passive, long-term investment rather than an activist position. While a significant institutional stake can be seen as a vote of confidence, this amendment does not provide new operational or financial information about AMG that would warrant a change in investment thesis. Therefore, a 'hold' recommendation is appropriate, maintaining current positions based on existing fundamental analysis of AMG, as this filing does not introduce new catalysts for significant upside or downside.

Keywords

Affiliated Managers Group, AMG, Clarkston Capital Partners, Beneficial Ownership, Schedule 13G, Investment Adviser, Common Stock, Institutional Ownership, SEC Filing