Comparable stake leader
MORGAN STANLEY
SEC ownership of AFFILIATED MANAGERS GROUP, INC.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001004434.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
15 Apr 2026
- Public ticker
- AMG, MGR, MGRB, MGRD, MGRE on NYSE
- Parsed ownership sources
- 13F, 13D/G, and 3/4/5
- Largest SEC-reported holder
- MORGAN STANLEY
- Latest 13D/G holder
- MORGAN STANLEY
- Latest parsed ownership date
- 15 Apr 2026
- Issuer CIK
- 0001004434
- Issuer location
- Jupiter, FL
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of AFFILIATED MANAGERS GROUP, INC. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
MORGAN STANLEY
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
15 Apr 2026
13F
13D/G
3/4/5
Lead comparable stake: 7%
13D/G row: MORGAN STANLEY
Showing 1-8 of 50 holder rows.
Quick read
MORGAN STANLEY leads the comparable SEC ownership view at 7%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens MORGAN STANLEY's linked filing trail.
Comparable ownership
Top 5
MORGAN STANLEY
7%
VANGUARD CAPITAL MANAGEMENT LLC
5.2%
VANGUARD PORTFOLIO MANAGEMENT LLC
5.1%
INTEGRATED CORE STRATEGIES (US) LLC
3.6%
Clarkston Capital Partners, LLC
3.2%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| MORGAN STANLEY |
13F
13D/G
Company
|
7%
from 13D/G
|
$479,386,628
1,732,512 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
5.2%
|
$383,712,065
1,386,744 shares
|
$0 | 31 Mar 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
13F
Vanguard Portfolio Management · Company
|
5.1%
|
$378,644,581
1,368,430 shares
|
$0 | 31 Mar 2026 |
| INTEGRATED CORE STRATEGIES (US) LLC |
13D/G
Millennium Management LLC
|
3.6%
|
$242,510,253
1,017,113 shares
|
-$116,590,124 | 30 Sep 2025 |
| Clarkston Capital Partners, LLC |
13D/G
13F
Company
|
3.2%
|
$260,639,425
904,119 shares
|
-$192,591,220 | 31 Dec 2025 |
| Cheerag B. Patel |
3/4/5
Head of Affiliate Engagement
|
0.15%
|
$10,973,645
39,659 shares
|
— | 15 Apr 2026 |
| BlackRock, Inc. |
13F
Company
|
11%
|
$793,482,850
2,867,665 shares
|
— | 31 Mar 2026 |
| ARIEL INVESTMENTS, LLC |
13F
Company
|
4%
|
$294,417,101
1,064,030 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$13,169,322.
Buys
$687,405
Insiders: 2
Sells
$13,856,727
Insiders: 5
Net
-$13,169,322
Shares: -45,852
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 2,250
Shares: 48,102
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 2,250 | 21,902 | $687,405 | $7,257,719 | -$6,570,314 |
| 3-6 | 0 | 10,200 | $0 | $2,902,528 | -$2,902,528 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 16,000 | $0 | $3,696,480 | -$3,696,480 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-19 of 19 reporting-owner rows connected to AFFILIATED MANAGERS GROUP, INC.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
19
Largest Forms 3/4/5 holder
Jay C. Horgen
Net 12M change
-$13,169,322
Latest report
08 Jun 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Jay C. Horgen | President and CEO, Director | $239,436,440 | -$5,919,725 | -2.4% | Mixed | 08 Jun 2026 |
| Thomas M. Wojcik | President and COO | $46,632,577 | -$5,986,880 | -11% | Mixed | 05 Mar 2026 |
| Rizwan M. Jamal | Head of Affiliate Investments | $37,117,022 | Mixed | 16 Oct 2024 | ||
| Kavita Padiyar | General Counsel & Corp. Sec. | $12,087,333 | -$612,128 | -4.8% | Mixed | 05 Mar 2026 |
| Cheerag B. Patel | Head of Affiliate Engagement | $10,973,645 | Median | 15 Apr 2026 | ||
| John R. Erickson | Head of Affiliate Engagement | $8,790,537 | Mixed | 15 Aug 2023 | ||
| Dwight D. Churchill | Director | $7,074,221 | Mixed | 15 Aug 2025 | ||
| Reuben Jeffery III | Director | $7,049,216 | Mixed | 01 Jan 2025 | ||
| Tracy P. Palandjian | Director | $5,433,583 | Mixed | 05 Mar 2026 | ||
| Karen L. Alvingham | Director | $5,072,581 | Mixed | 05 Mar 2026 | ||
| David M. Billings | General Counsel and Secretary | $2,871,680 | Mixed | 15 Nov 2022 | ||
| G. Staley Cates | Director | $1,958,841 | +$458,745 | +31% | Filing P/S | 06 May 2026 |
| Rodriguez Felix Matos V | Director | $1,893,437 | -$300,180 | -14% | Mixed | 08 May 2026 |
| David Christopher Ryan | Director | $1,409,153 | -$1,037,814 | -42% | Mixed | 06 May 2026 |
| Tracy A. Atkinson | Director | $1,251,789 | Mixed | 05 Mar 2024 | ||
| Loren M. Starr | Director | $1,217,911 | Mixed | 05 Mar 2026 | ||
| Annette Franqui | Director | $697,461 | +$228,660 | +49% | Mixed | 01 Jun 2026 |
| Dava Ritchea | Chief Financial Officer | $493,852 | Mixed | 05 Mar 2026 | ||
| Marcy Engel | Director | Mixed | 05 Mar 2026 |
Recent insider transactions for AFFILIATED MANAGERS GROUP, INC.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Jay C. Horgen | AMG | Common Stock | Sale | -7.88% | $5,919,725 | $338.27 | -17,500 | 204,706 | 08 Jun 2026 | Direct |
| Jay C. Horgen | AMG | Common Stock | Tax liability | -15.2% | -39,671 | 222,206 | 08 Jun 2026 | Direct | ||
| Jay C. Horgen | AMG | Common Stock | Options Exercise | 40.1% | 75,000 | 261,877 | 08 Jun 2026 | Direct | ||
| Jay C. Horgen | AMG | Employee Stock Option (Right to Buy) | Options Exercise | -100% | -75,000 | 0 | 08 Jun 2026 | Direct | ||
| Annette Franqui | AMG | Common Stock | Purchase | 61.9% | $228,660 | $304.88 | 750 | 1,962 | 01 Jun 2026 | Direct |
| Rodriguez Felix Matos V | AMG | Common Stock | Sale | -18.6% | $300,180 | $300.18 | -1,000 | 4,369 | 08 May 2026 | Direct |
| David Christopher Ryan | AMG | Common Stock | Sale | -75.7% | $1,037,814 | $305.06 | -3,402 | 1,092 | 06 May 2026 | Direct |
| G. Staley Cates | AMG | Common Stock | Purchase | 30.6% | $458,745 | $305.83 | 1,500 | 6,405 | 06 May 2026 | Direct |
| G. Staley Cates | AMG | Stock Units | Award | 172 | 172 | 01 May 2026 | Direct | |||
| Kavita Padiyar | AMG | Common Stock | Sale | -4.9% | $612,128 | $278.24 | -2,200 | 42,672 | 09 Mar 2026 | Direct |
| Thomas M. Wojcik | AMG | Common Stock | Sale | -4.78% | $2,290,400 | $286.30 | -8,000 | 159,465 | 06 Mar 2026 | Direct |
| Thomas M. Wojcik | AMG | Common Stock | Tax liability | -5.17% | -9,136 | 167,465 | 05 Mar 2026 | Direct | ||
| Thomas M. Wojcik | AMG | Common Stock | Award | 6.4% | 10,619 | 176,601 | 05 Mar 2026 | Direct | ||
| Thomas M. Wojcik | AMG | Common Stock | Options Exercise | 4.58% | 7,272 | 165,982 | 05 Mar 2026 | Direct | ||
| Thomas M. Wojcik | AMG | Stock Units | Options Exercise | -43.2% | -7,272 | 9,546 | 05 Mar 2026 | Direct | ||
| Kavita Padiyar | AMG | Common Stock | Tax liability | -4.84% | -2,282 | 44,872 | 05 Mar 2026 | Direct | ||
| Kavita Padiyar | AMG | Common Stock | Award | 5.42% | 2,426 | 47,154 | 05 Mar 2026 | Direct | ||
| Kavita Padiyar | AMG | Common Stock | Options Exercise | 5.39% | 2,288 | 44,728 | 05 Mar 2026 | Direct | ||
| Kavita Padiyar | AMG | Stock Units | Award | 1,191 | 1,191 | 05 Mar 2026 | Direct | |||
| Kavita Padiyar | AMG | Stock Units | Options Exercise | -46.2% | -2,288 | 2,670 | 05 Mar 2026 | Direct | ||
| Jay C. Horgen | AMG | Common Stock | Tax liability | -5.16% | -18,333 | 336,877 | 05 Mar 2026 | Direct | ||
| Jay C. Horgen | AMG | Common Stock | Award | 8.31% | 27,260 | 355,210 | 05 Mar 2026 | Direct | ||
| Jay C. Horgen | AMG | Common Stock | Options Exercise | 5.66% | 17,563 | 327,950 | 05 Mar 2026 | Direct | ||
| Jay C. Horgen | AMG | Stock Units | Award | 8,544 | 8,544 | 05 Mar 2026 | Direct | |||
| Jay C. Horgen | AMG | Stock Units | Options Exercise | -43.4% | -17,563 | 22,891 | 05 Mar 2026 | Direct | ||
| Dava Ritchea | AMG | Common Stock | Tax liability | -48.6% | -292 | 309 | 05 Mar 2026 | Direct | ||
| Dava Ritchea | AMG | Common Stock | Options Exercise | 601 | 601 | 05 Mar 2026 | Direct | |||
| Dava Ritchea | AMG | Stock Units | Award | 1,667 | 1,667 | 05 Mar 2026 | Direct | |||
| Dava Ritchea | AMG | Stock Units | Options Exercise | -25% | -601 | 1,804 | 05 Mar 2026 | Direct | ||
| Karen L. Alvingham | AMG | Common Stock | Tax liability | -0.51% | -67 | 13,043 | 05 Mar 2026 | Direct | ||
| Karen L. Alvingham | AMG | Common Stock | Options Exercise | 7.08% | 867 | 13,110 | 05 Mar 2026 | Direct | ||
| Karen L. Alvingham | AMG | Deferred Stock Units | Award | 98 | 98 | 05 Mar 2026 | Direct | |||
| Karen L. Alvingham | AMG | Stock Units | Award | 171 | 171 | 05 Mar 2026 | Direct | |||
| Karen L. Alvingham | AMG | Stock Units | Options Exercise | -19% | -867 | 3,709 | 05 Mar 2026 | Direct | ||
| David Christopher Ryan | AMG | Common Stock | Options Exercise | 23.9% | 867 | 4,494 | 05 Mar 2026 | Direct | ||
| David Christopher Ryan | AMG | Stock Units | Award | 335 | 335 | 05 Mar 2026 | Direct | |||
| David Christopher Ryan | AMG | Stock Units | Options Exercise | -18.4% | -867 | 3,850 | 05 Mar 2026 | Direct | ||
| Loren M. Starr | AMG | Common Stock | Options Exercise | 50.7% | 652 | 1,937 | 05 Mar 2026 | Direct | ||
| Loren M. Starr | AMG | Deferred Stock Units | Award | 257 | 257 | 05 Mar 2026 | Direct | |||
| Loren M. Starr | AMG | Stock Units | Award | 503 | 503 | 05 Mar 2026 | Direct | |||
| Loren M. Starr | AMG | Stock Units | Options Exercise | -21.6% | -652 | 2,362 | 05 Mar 2026 | Direct | ||
| Marcy Engel | AMG | Stock Units | Award | 335 | 335 | 05 Mar 2026 | Direct | |||
| Rodriguez Felix Matos V | AMG | Common Stock | Options Exercise | 19.3% | 867 | 5,369 | 05 Mar 2026 | Direct | ||
| Rodriguez Felix Matos V | AMG | Stock Units | Award | 335 | 335 | 05 Mar 2026 | Direct | |||
| Rodriguez Felix Matos V | AMG | Stock Units | Options Exercise | -42.5% | -867 | 1,172 | 05 Mar 2026 | Direct | ||
| Tracy P. Palandjian | AMG | Common Stock | Options Exercise | 6.03% | 867 | 15,254 | 05 Mar 2026 | Direct | ||
| Tracy P. Palandjian | AMG | Stock Units | Award | 335 | 335 | 05 Mar 2026 | Direct | |||
| Tracy P. Palandjian | AMG | Stock Units | Options Exercise | -30.6% | -867 | 1,970 | 05 Mar 2026 | Direct | ||
| Annette Franqui | AMG | Common Stock | Options Exercise | 82.5% | 548 | 1,212 | 05 Mar 2026 | Direct | ||
| Annette Franqui | AMG | Stock Units | Award | 335 | 335 | 05 Mar 2026 | Direct |
* marks a reported price that did not pass the local price check.