AFFILIATED MANAGERS GROUP (AMG) Stock Institutional Trading Activity


AFFILIATED MANAGERS GROUP (AMG) position changes reported by tracked institutional filers across multiple SEC 13F reporting periods. Based on recent SEC 13F filings (Q4 2025), investors with some of the largest reported share count changes include Ariel Appreciation Fund, Renaissance Technologies LLC, Longleaf Partners, Sequoia Financial Advisors, and Dodge & Cox Stock Fund. Explore insights into buying and selling patterns, position changes, and investment conviction levels to understand institutional trading behavior and market dynamics.

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Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q1 2021Renaissance Technologies LLCSell-67,08613,114$1,954
Q1 2021Ariel Appreciation FundBuy34,149825,603$123,040
Q1 2021Longleaf PartnersSell-346,7821,270,837$189,393
Q4 2020Renaissance Technologies LLCSell-28,50080,200$8,156
Q4 2020Longleaf PartnersBuy215,9951,617,619$164,511
Q4 2020Ariel Appreciation FundBuy42,033791,454$80,491
Q3 2020Renaissance Technologies LLCBuy15,200108,700$7,433
Q3 2020Longleaf PartnersBuy14,5101,401,624$95,843
Q3 2020Ariel Appreciation FundBuy132749,421$51,245
Q2 2020Renaissance Technologies LLCSell-336,68193,500$6,971
Q2 2020Longleaf PartnersSell-14,7861,387,114$103,423
Q2 2020Ariel Appreciation FundBuy90,135749,289$55,867
Q1 2020Arbiter Partners Capital ManagementBuy4,0006,000$355
Q1 2020Renaissance Technologies LLCSell-597,411430,181$25,441
Q1 2020Longleaf PartnersBuy6011,401,900$82,908
Q1 2020Ariel Appreciation FundBuy66,456659,154$38,982
Q4 2019Renaissance Technologies LLCBuy21,8921,027,592$87,078
Q4 2019Longleaf PartnersSell-120,6981,401,299$118,747
Q4 2019Ariel Appreciation FundBuy5,975592,698$50,225
Q3 2019Renaissance Technologies LLCSell-68,2001,005,700$83,825
Q3 2019Longleaf PartnersSell-77,3921,521,997$126,858
Q3 2019Ariel Appreciation FundBuy129,170586,723$48,903
Q2 2019Renaissance Technologies LLCSell-206,1001,073,900$98,949
Q2 2019Longleaf PartnersSell-92,4161,599,389$147,368
Q2 2019Ariel Appreciation FundBuy52,139457,553$42,159
Q1 2019Arbiter Partners Capital ManagementSell-31,5852,000$214
Q1 2019Renaissance Technologies LLCBuy317,7001,280,000$137,101
Q1 2019Longleaf PartnersSell-147,8111,691,805$181,209
Q1 2019Ariel Appreciation FundBuy2,389405,414$43,424
Q4 2018Jensen Investment ManagementBuy2,4006,860$668

Frequently asked questions about AMG activity

  • Which institutional owners are buying AMG?

    Institutional owners buying AMG include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in AMG activity?

    "Buy" means an investor increased their reported position in AMG compared to the prior reporting period. This reflects growing exposure to AFFILIATED MANAGERS GROUP (AMG) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in AMG increasing?

    Institutional interest in AMG can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.