Affiliated Managers Group, Inc.
Affiliated Managers Group, Inc. (AMG) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · AMG · as of Sep 30, 2025
Ownership Breakdown
455
Institutional Holders
▲ 17 vs Q2
$6.31B
Total Inst. Value
▲ $1.03B vs Q2
26.41M
Shares Outstanding
freeFloat 96.13%
26.61M
13F Shares Held
▼ 220,524 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
AMG largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
BLACKROCK, INC. investment advice | 2.82M | 9.76% | 9.76% | $672.81B | Nov 12, 2025 | ▼ 845 |
VANGUARD GROUP INC investment advice | 2.77M | 9.59% | 9.59% | $660.99B | Nov 7, 2025 | ▼ 39.8K |
MORGAN STANLEY investment advice | 1.94M | 6.72% | 6.72% | $462.92B | May 27, 2026 | ▼ 76.0K |
ARIEL INVESTMENTS, LLC investment advice | 1.26M | 4.37% | 4.37% | $301.33B | Nov 14, 2025 | ▼ 91.3K |
CLARKSTON CAPITAL PARTNERS, LLC investment advice | 1.23M | 4.26% | 4.26% | $293.83B | Nov 13, 2025 | ▼ 203.0K |
BOSTON PARTNERS investment advice | 1.16M | 4.00% | 4.00% | $275.96B | Nov 13, 2025 | ▲ 24.2K |
MILLENNIUM MANAGEMENT LLC investment advice | 1.02M | 3.52% | 3.52% | $242.51B | Nov 14, 2025 | ▼ 552.2K |
STATE STREET CORP investment advice | 963.7K | 3.33% | 3.33% | $229.78B | Nov 14, 2025 | ▼ 17.2K |
DIMENSIONAL FUND ADVISORS LP investment advice | 684.1K | 2.37% | 2.37% | $163.11B | Nov 12, 2025 | ▲ 7.9K |
CITADEL ADVISORS LLC investment advice | 645.1K | 2.23% | 2.23% | $153.82B | Nov 14, 2025 | ▲ 5.4K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
25
Increased
+975.0K shares2
New Positions
first time holders23
Decreased
−1.21M shares0
Sold Out
fully exitedNet shares change (top 50)
238.7K
+975.0K / −1.21M
Net new holders
+4
2 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
AMG insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
2
Buy transactions
2
Sell transactions
1.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Matos Rodriguez Felix V. director | May 8, 2026 | Sale | 1,000 | $300.18 | $300.2K | 4.4K | Form 4 ↗ |
Ryan David Christopher director | May 6, 2026 | Sale | 3,402 | $305.06 | $1.04M | 1.1K | Form 4 ↗ |
Cates G. Staley director | May 6, 2026 | Purchase | 1,500 | $305.83 | $458.7K | 6.4K | Form 4 ↗ |
Cates G. Staley director | May 1, 2026 | Award | 172 | — | — | 172 | Form 4 ↗ |
Wojcik Thomas M President and COO | Mar 5, 2026 | Award | 10,619 | — | — | 176.6K | Form 4 ↗ |
Wojcik Thomas M President and COO | Mar 5, 2026 | Tax Withhold | 9,136 | $299.18 | $2.73M | 167.5K | Form 4 ↗ |
Wojcik Thomas M President and COO | Mar 6, 2026 | Sale | 8,000 | $286.30 | $2.29M | 159.5K | Form 4 ↗ |
Padiyar Kavita General Counsel & Corp. Sec. | Mar 5, 2026 | Award | 2,426 | — | — | 47.2K | Form 4 ↗ |
Padiyar Kavita General Counsel & Corp. Sec. | Mar 5, 2026 | Tax Withhold | 2,282 | $299.18 | $682.7K | 44.9K | Form 4 ↗ |
Padiyar Kavita General Counsel & Corp. Sec. | Mar 9, 2026 | Sale | 2,200 | $278.24 | $612.1K | 42.7K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Affiliated Managers Group, Inc. (AMG) is primarily owned by institutional investors, who hold approximately 100.0% of total shares outstanding. Company insiders own approximately 3.87%, while retail and public investors account for the remaining 0.00%.
The largest institutional shareholder of Affiliated Managers Group, Inc. is BLACKROCK, INC., holding approximately 2.82 million shares — equal to 9.76% of outstanding shares — as of September 30, 2025.
A total of 455 institutional investors currently hold AMG stock, with a combined institutional value of approximately $6.31 billion as of the most recent 13F filing period.
Frequently asked questions
AMG ownershipAffiliated Managers Group, Inc. (AMG) is primarily owned by institutional investors, who hold approximately 100.0% of shares. The largest shareholder is BLACKROCK, INC. with a 9.76% stake. Company insiders hold 3.87%. Data sourced from SEC Form 13F as of September 30, 2025.