AMS Institutional Ownership & Shareholders
AMERICAN SHARED HOSPITAL SER (AMS) is currently held by 17 institutional investors tracked by InsiderSet, with a combined reported market value of approximately $758,563 based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Dimensional Fund Advisors Lp is currently the largest disclosed institutional shareholder of AMS tracked by InsiderSet, reporting ownership valued at approximately $144,846 in its September 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $118,324.64, representing an estimated loss of -18.31% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 90% of the total disclosed AMS value among the investors covered in this analysis. Major shareholders include Dimensional Fund Advisors Lp, Lpl Financial Llc, Renaissance Technologies LLC, and several other long-term asset managers with concentrated positions in AMERICAN SHARED HOSPITAL SER (AMS).
This page ranks the largest institutional AMS 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
17
Total Reported Value
$758,563
Largest Holder
Dimensional Fund Advisors Lp
Largest Position
$144,846
Insider Transactions (90d)
0
Latest Filing Quarter
Q2 2026
New Institutional Positions
26
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Dimensional Fund Advisors Lp | 0.00% | 102,004 | $144,846 | $118,325 | -$26,521 | -18.31% | |
| Lpl Financial Llc | 0.00% | 81,386 | $115,568 | $94,408 | -$21,160 | -18.31% | |
| Renaissance Technologies LLC | Jim Simons | 0.00% | 57,695 | $91,158 | $66,926 | -$24,232 | -26.58% |
| Vanguard Capital Management Llc | 0.00% | 55,662 | $87,946 | $64,568 | -$23,378 | -26.58% | |
| Newedge Advisors, Llc | 0.00% | 29,725 | $46,966 | $34,481 | -$12,485 | -26.58% | |
| Bridgeway Capital Management, Llc | 0.00% | 29,124 | $46,016 | $33,784 | -$12,232 | -26.58% | |
| James Investment Research, Inc. | 0.00% | 29,725 | $42,210 | $34,481 | -$7,729 | -18.31% | |
| Vanguard Fiduciary Trust Co | 0.00% | 25,363 | $40,074 | $29,421 | -$10,653 | -26.58% | |
| Geode Capital Management, Llc | 0.00% | 26,036 | $36,993 | $30,202 | -$6,791 | -18.36% | |
| Xtx Topco Ltd | 0.00% | 19,107 | $30,189 | $22,164 | -$8,025 | -26.58% | |
| Ubs Group Ag | 0.00% | 18,395 | $29,064 | $21,338 | -$7,726 | -26.58% | |
| State Street Corp | 0.00% | 12,101 | $19,120 | $14,037 | -$5,083 | -26.58% | |
| Empowered Funds, Llc | 0.00% | 11,924 | $18,840 | $13,832 | -$5,008 | -26.58% | |
| Morgan Stanley | 0.00% | 5,858 | $9,256 | $6,795 | -$2,461 | -26.59% | |
| Jones Financial Companies Lllp | 0.00% | 100 | $161 | $116 | -$45 | -27.95% | |
| Caitong International Asset Management Co., Ltd | 0.00% | 107 | $152 | $124 | -$28 | -18.34% | |
| Barclays Plc | 0.00% | 3 | $4 | $3 | -$1 | -13.00% |
Frequently asked questions about AMS
Who are the largest institutional holders of AMS?
The largest institutional holders of AMS reported in the latest SEC Form 13F filings include Dimensional Fund Advisors Lp, Lpl Financial Llc, Renaissance Technologies LLC, Vanguard Capital Management Llc, and Newedge Advisors, Llc. InsiderSet ranks institutional holders by their latest reported AMS position.
What is AMS institutional ownership?
This page tracks AMS positions reported by institutional investment managers through SEC Form 13F. AMERICAN SHARED HOSPITAL SER (AMS) institutional ownership on InsiderSet reflects disclosed 13F holdings among the managers we analyze, not every shareholder of the stock.
How many institutions own AMS?
InsiderSet currently tracks 17 institutional managers reporting AMS 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 AMS shareholders.
How much AMS stock do institutions own?
Institutional investment managers disclosed approximately $758,563 in AMS holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value.
When was AMS institutional ownership last updated?
The latest AMS 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 AMS 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 AMS position after the reporting date.
Are institutions buying or selling AMS?
Institutional buying and selling can be analyzed by comparing AMS positions across consecutive 13F reporting periods. InsiderSet's AMS Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View AMS ownership changes.
How has AMS institutional ownership changed over time?
InsiderSet tracks AMS institutional holdings across multiple 13F reporting periods, allowing investors to compare institutional holder counts, reported value, and reported shares over time.