ARIMX Institutional Ownership & Shareholders
AMG RR SMID VAL-I (ARIMX) is currently held by 6 institutional investors tracked by InsiderSet, with a combined reported market value of approximately $33.24M based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Hemenway Trust Co Llc is currently the largest disclosed institutional shareholder of ARIMX tracked by InsiderSet, reporting ownership valued at approximately $19.50M in its June 30, 2026 SEC Form 13F filing.
The top 10 institutional shareholders tracked on this page collectively account for approximately 100% of the total disclosed ARIMX value among the investors covered in this analysis. Major shareholders include Hemenway Trust Co Llc, Broderick Brian C, Somerville Kurt F, and several other long-term asset managers with concentrated positions in AMG RR SMID VAL-I (ARIMX).
This page ranks the largest institutional ARIMX shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
6
Total Reported Value
$33.24M
Largest Holder
Hemenway Trust Co Llc
Largest Position
$19.50M
Insider Transactions (90d)
0
Latest Filing Quarter
Q2 2026
New Institutional Positions
6
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Hemenway Trust Co Llc | 1.36% | 1,846,391 | $19,497,884 | — | — | — | |
| Broderick Brian C | 1.10% | 673,406 | $7,111,167 | — | — | — | |
| Somerville Kurt F | 0.66% | 259,951 | $2,745,077 | — | — | — | |
| Dempze Nancy E | 1.28% | 252,648 | $2,667,962 | — | — | — | |
| Elefante Mark B | 0.36% | 78,815 | $832,293 | — | — | — | |
| Delaney Dennis R | 0.12% | 36,219 | $382,470 | — | — | — |
Frequently asked questions about ARIMX
Who are the largest institutional holders of ARIMX?
The largest institutional holders of ARIMX reported in the latest SEC Form 13F filings include Hemenway Trust Co Llc, Broderick Brian C, Somerville Kurt F, Dempze Nancy E, and Elefante Mark B. InsiderSet ranks institutional holders by their latest reported ARIMX position.
What is ARIMX institutional ownership?
This page tracks ARIMX positions reported by institutional investment managers through SEC Form 13F. AMG RR SMID VAL-I (ARIMX) institutional ownership on InsiderSet reflects disclosed 13F holdings among the managers we analyze, not every shareholder of the stock.
How many institutions own ARIMX?
InsiderSet currently tracks 6 institutional managers reporting ARIMX holdings in the latest available 13F data. This count reflects institutions included in the SEC Form 13F filings analyzed by InsiderSet and should not be interpreted as the total number of ARIMX shareholders.
How much ARIMX stock do institutions own?
Institutional investment managers disclosed approximately $33.24M in ARIMX holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value.
When was ARIMX institutional ownership last updated?
The latest ARIMX institutional ownership data on InsiderSet is based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time institutional holdings.
Are institutional ARIMX holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by institutional investment managers as of the end of the reporting quarter. An institution may have changed its ARIMX position after the reporting date.
Are institutions buying or selling ARIMX?
Institutional buying and selling can be analyzed by comparing ARIMX positions across consecutive 13F reporting periods. InsiderSet's ARIMX Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View ARIMX ownership changes.
How has ARIMX institutional ownership changed over time?
InsiderSet tracks ARIMX institutional holdings across multiple 13F reporting periods, allowing investors to compare institutional holder counts, reported value, and reported shares over time.