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Affiliated Managers Group, Inc.

AMG
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SEC CIK
0001004434

No open-market purchases or sales by Affiliated Managers Group, Inc. insiders were filed in the last 90 days; 571 institutions reported holding it in 13F filings for Q2 2026, worth $8.53B in total; Southeastern Asset Management (Longleaf) is the only superinvestor holding it.

Other share classesMGRMGRBMGRDMGRE

Holders of 5% or more of AMG

Holders whose latest Schedule 13D or 13G filing reports 5% or more of Affiliated Managers Group, Inc., largest stake first. The change is against the holder's previous filing.

Holders of 5% or more of AMG
HolderLatest formStakeChangeFirst filedLatest filingFiling
Morgan Stanley13G/A5.50%1.46M shares−1.50 ppfrom 7.00%Dec 10, 20217 filingsAug 12, 2026SEC
Vanguard Capital Management LLC13G5.19%1.39M sharesNewApr 29, 20261 filingApr 29, 2026SEC
Vanguard Portfolio Management LLC13G5.12%1.37M sharesNewApr 28, 20261 filingApr 28, 2026SEC

Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.

13D and 13G filings

36 Schedule 13D and 13G filings on Affiliated Managers Group, Inc., newest first, including old-format filings without a stake.

Schedule 13D and 13G filings on AMG
Filed (ET)FilerFormStakeChangeEvent dateFiling
Aug 12, 20262:52 PM ETMorgan Stanleyand 1 other13G/A5.50%1.46M shares−1.50 ppfrom 7.00%Jun 30, 2026SEC
Apr 29, 20264:41 PM ETVanguard Capital Management LLC13G5.19%1.39M sharesNewMar 31, 2026SEC
Apr 28, 20263:49 PM ETVanguard Portfolio Management LLC13G5.12%1.37M sharesNewMar 31, 2026SEC
Mar 26, 20262:17 PM ETVanguard Group Inc13G/A0.00%0 shares−10.20 ppfrom 10.20%Below 5%Mar 13, 2026SEC
Mar 5, 20261:19 PM ETVanguard Group Inc13G/A10.20%2.72M shares+0.45 ppfrom 9.75%Feb 27, 2026SEC
Feb 13, 20268:00 AM ETClarkston Capital Partners, LLCand 5 others13G/A3.21%904.1K shares−1.99 ppfrom 5.20%Below 5%Dec 31, 2025SEC
Nov 7, 202512:16 PM ETMorgan Stanleyand 2 others13G/A7.00%1.98M shares–Sep 30, 2025SEC
Oct 30, 20254:19 PM ETIntegrated Core Strategies (US) LLCand 3 others13G/A3.60%1.02M shares−1.70 ppfrom 5.30%Below 5%Sep 30, 2025SEC
Oct 30, 20252:26 PM ETVanguard Group Inc13G/A9.75%2.77M shares–Sep 30, 2025SEC
Jun 6, 20254:00 PM ETIntegrated Core Strategies (US) LLCand 3 others13G5.30%1.51M shares+1.00 ppfrom 4.30%Jun 2, 2025SEC
May 14, 20254:00 PM ETIntegrated Core Strategies (US) LLCand 3 others13G4.30%1.22M sharesNewBelow 5%May 7, 2025SEC
Feb 14, 202511:47 AM ETClarkston Capital Partners, LLCand 5 others13G/A5.20%1.57M shares–Dec 31, 2024SEC
Nov 6, 2024Morgan Stanley13G/AOld format–––SEC
Jun 7, 20241:30 PM ETBlackRock Inc.13G/AOld format–––SEC
Feb 14, 2024EdgePoint Investment Group Inc.13G/AOld format–––SEC
Feb 13, 2024Vanguard Group Inc13G/AOld format–––SEC
Feb 12, 2024Clarkston Capital Partners, LLC13G/AOld format–––SEC
Feb 12, 2024Morgan Stanley13G/AOld format–––SEC
Jan 24, 20242:27 PM ETBlackRock Inc.13G/AOld format–––SEC
Dec 6, 20234:47 PM ETBlackRock Inc.13G/AOld format–––SEC
Feb 14, 2023Clarkston Capital Partners, LLC13GOld format–New–SEC
Feb 9, 2023Vanguard Group Inc13G/AOld format–––SEC
Feb 8, 2023Morgan Stanley13G/AOld format–––SEC
Jan 24, 20231:56 PM ETBlackRock Inc.13G/AOld format–––SEC
Jan 10, 2023EdgePoint Investment Group Inc.13G/AOld format–––SEC
Nov 10, 2022Vanguard Group Inc13G/AOld format–––SEC
Feb 11, 2022EdgePoint Investment Group Inc.13G/AOld format–––SEC
Feb 9, 2022Vanguard Group Inc13G/AOld format–––SEC
Feb 9, 2022Morgan Stanley13G/AOld format–––SEC
Feb 1, 20225:08 PM ETBlackRock Inc.13G/AOld format–––SEC
Dec 10, 202110:05 AM ETBlackRock Inc.13G/AOld format–––SEC
Dec 10, 2021Morgan Stanley13G/AOld format–––SEC
Feb 16, 2021Eaton Vance Management13GOld format–New–SEC
Feb 12, 2021EdgePoint Investment Group Inc.13G/AOld format–––SEC
Feb 10, 2021Vanguard Group Inc13G/AOld format–––SEC
Jan 28, 20215:56 PM ETBlackRock Inc.13G/AOld format–––SEC

Form 144: proposed insider sales

12 notices from officers, directors and other affiliates planning to sell Affiliated Managers Group, Inc. shares, newest first.

Form 144 notices for AMG
Filed (ET)SellerShares to sellMarket valuePlanned saleBrokerFiling
Jun 30, 20264:07 PM ETDavid RyanDirector305$104.9KJun 30, 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesSEC
Jun 8, 20264:17 PM ETJay HorgenOfficer17.5K$5.92MJun 8, 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesSEC
May 8, 20264:06 PM ETFelix V Matos RodriguezDirector1.00K$300.2KMay 8, 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesSEC
May 6, 20264:13 PM ETDavid RyanDirector3.40K$1.04MMay 6, 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesSEC
Mar 9, 20264:05 PM ETKavita PadiyarOfficer2.20K$612.1KMar 9, 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesSEC
Mar 9, 20261:02 PM ETWojcik Thomas MOfficer46.9K$13.1MMar 9, 2026Fidelity Brokerage Services LLCSEC
Mar 6, 20264:15 PM ETThomas WojcikOfficer8.00K$2.29MMar 6, 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesSEC
Sep 9, 20254:06 PM ETThomas WojcikOfficer16.0K$3.70MSep 9, 2025Morgan Stanley Smith Barney LLC Executive Financial ServicesSEC
Mar 10, 20258:52 PM ETRizwan M. JamalFormer officer14.7K$2.30MMar 10, 2025J.P. Morgan Securities LLCSEC
Aug 19, 202410:11 AM ETHorgen Jay C.Officer18.3K$3.16MAug 19, 2024Fidelity Brokerage Services LLCSEC
Aug 16, 20245:53 PM ETRizwan M. JamalAffiliate8.62K$1.48MAug 16, 2024J.P. Morgan Securities LLCSEC
Aug 16, 202411:25 AM ETWojcik Thomas MOfficer4.79K$820.7KAug 16, 2024FIDELITY BROKERAGE SERVICES LLCSEC