Affiliated Managers Group, Inc. (AMG) Institutional Ownership

Ownership Summary

Affiliated Managers Group, Inc. (NYSE:AMG) has 501 institutional investors with active 13F positions as of December 2025.

• Collectively, these holders controlled 80.5% of Affiliated Managers's outstanding shares in December 2025, down from 82.0% in September 2025.
• Their total shares held in AMG increased 0.49% from the prior quarter, while the number of investors in Affiliated Managers increased 24.63% year over year.
• Of these 501 holders, 239 added to their stakes in Affiliated Managers, 170 trimmed positions, and 92 made no changes.
• Institutional investors collectively held 26.57Mn shares in Affiliated Managers as of December 2025, up by 128.31K shares quarter on quarter, and down 4.8Mn shares year over year.
• As of December 31, 2025, the biggest holder of Affiliated Managers is BlackRock, Inc. at 2.87Mn shares, representing 8.69% of shares outstanding.
• Top purchasers of AMG stock for the quarter ending December 2025 included VANGUARD PORTFOLIO MANAGEMENT LLC (1.36Mn), VANGUARD CAPITAL MANAGEMENT LLC (1.17Mn), Invesco Ltd. (219.77K), JANE STREET GROUP, LLC (212.43K), PRICE T ROWE ASSOCIATES INC /MD/ (183.62K).
• The biggest sellers of Affiliated Managers for the quarter ending December 2025 included MILLENNIUM MANAGEMENT LLC (790.64K), FULLER & THALER ASSET MANAGEMENT, INC. (610.96K), Clarkston Capital Partners, LLC (590.41K), NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO (193.38K), UBS Group AG (166.3K).
• Per Business Quant, the top 10 investors in AMG for the quarter ending December 2025 include BlackRock, Inc. (2.87Mn), Morgan Stanley (1.73Mn), VANGUARD PORTFOLIO MANAGEMENT LLC (1.36Mn), VANGUARD CAPITAL MANAGEMENT LLC (1.17Mn), ARIEL INVESTMENTS, LLC (1.06Mn), Boston Partners (971.25K), State Street Corp (926.73K), FULLER & THALER ASSET MANAGEMENT, INC. (760.21K), DIMENSIONAL FUND ADVISORS LP (718.31K), GEODE CAPITAL MANAGEMENT, LLC (635.78K).