American Shared Hospital Services
American Shared Hospital Services (AMS) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · AMS · as of Sep 30, 2025
Ownership Breakdown
21
Institutional Holders
▲ 3 vs Q2
$3.47M
Total Inst. Value
▲ $1.42M vs Q2
6.63M
Shares Outstanding
freeFloat 57.38%
1.24M
13F Shares Held
▲ 388,786 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
AMS largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
services-medical laboratories | 410.7K | 6.24% | 6.24% | $1.15B | May 15, 2026 | NEW |
DIMENSIONAL FUND ADVISORS LP services-medical laboratories | 210.0K | 3.19% | 3.19% | $587.88M | Nov 12, 2025 | — held |
VANGUARD GROUP INC services-medical laboratories | 181.1K | 2.75% | 2.75% | $507.20M | Nov 7, 2025 | ▼ 100 |
CI PRIVATE WEALTH, LLC services-medical laboratories | 160.6K | 2.44% | 2.44% | $449.56M | Nov 14, 2025 | — held |
BRIDGEWAY CAPITAL MANAGEMENT, LLC services-medical laboratories | 96.7K | 1.47% | 1.47% | $270.74M | Nov 14, 2025 | — held |
RENAISSANCE TECHNOLOGIES LLC services-medical laboratories | 49.8K | 75.66% | 75.66% | $139.44M | Nov 13, 2025 | ▼ 16.9K |
GEODE CAPITAL MANAGEMENT, LLC services-medical laboratories | 32.7K | 49.63% | 49.63% | $91.50M | Nov 12, 2025 | ▼ 427 |
JAMES INVESTMENT RESEARCH INC services-medical laboratories | 29.7K | 45.16% | 45.16% | $83.23M | Oct 31, 2025 | — held |
NEWEDGE ADVISORS, LLC services-medical laboratories | 29.7K | 45.16% | 45.16% | $83.23M | Nov 17, 2025 | — held |
STATE STREET CORP services-medical laboratories | 12.1K | 18.38% | 18.38% | $33.88M | Nov 14, 2025 | — held |
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
1
Increased
+454 shares5
New Positions
first time holders6
Decreased
−18.6K shares2
Sold Out
fully exitedNet shares change (top 50)
18.2K
+454 / −18.6K
Net new holders
-2
5 new / 2 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
AMS insider trading · insider activity
Source: SEC Form 4
1
Buy transactions
0
Sell transactions
0.00
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 |
|---|---|---|---|---|---|---|---|
Stachowiak Raymond C Executive Chairman | Mar 26, 2026 | Award | 100,000 | — | — | 774.7K | Form 4 ↗ |
Stachowiak Raymond C Executive Chairman | Jun 26, 2025 | Award | 110,000 | — | — | 664.7K | Form 4 ↗ |
Tagawa Craig Kenji President | Apr 30, 2025 | Award | 5,613 | — | — | 35.5K | Form 4 ↗ |
Frech Raymond Scott Chief Financial Officer | Dec 19, 2024 | Award | 50,000 | — | — | 50.0K | Form 4 ↗ |
Delanois Gary Chief Operating Officer | Oct 14, 2024 | Award | 120,000 | — | — | 120.0K | Form 4 ↗ |
Stachowiak Raymond C Executive Chairman | Mar 22, 2024 | Award | 120,000 | — | — | 554.7K | Form 4 ↗ |
HIATT ROBERT L Chief Financial Officer | Apr 17, 2023 | Award | 20,000 | $2.78 | $55.6K | 20.0K | Form 4 ↗ |
Gaccione Peter M Chief Executive Officer | Mar 28, 2023 | Award | 50,000 | $2.93 | $146.5K | 50.0K | Form 4 ↗ |
Stachowiak Raymond C Executive Chairman | Mar 28, 2023 | Award | 120,000 | — | — | 536.2K | Form 4 ↗ |
Tagawa Craig Kenji President, CFO | Mar 7, 2023 | Award | 10,827 | — | — | 29.9K | 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
American Shared Hospital Services (AMS) is primarily owned by institutional investors, who hold approximately 18.7% of total shares outstanding. Company insiders own approximately 42.62%, while retail and public investors account for the remaining 38.65%.
The largest institutional shareholder of American Shared Hospital Services is , holding approximately 410,746 shares — equal to 6.24% of outstanding shares — as of September 30, 2025.
A total of 21 institutional investors currently hold AMS stock, with a combined institutional value of approximately $3,473,784 as of the most recent 13F filing period.
Frequently asked questions
AMS ownershipAmerican Shared Hospital Services (AMS) is primarily owned by institutional investors, who hold approximately 18.7% of shares. The largest shareholder is with a 6.24% stake. Company insiders hold 42.62%. Data sourced from SEC Form 13F as of September 30, 2025.