Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in AMS held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | National Philanthropic Trust | 411K | $1.2M | β | 6.200% | 0.00% |
| 2 | DIMENSIONAL FUND ADVISORS LP | 205K | $297K | -0.6% | 3.096% | 0.00% |
| 3 | Corient Private Wealth LLC | 161K | $233K | 0.0% | 2.423% | 0.00% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 154K | $223K | β | 2.321% | 0.00% |
| 5 | BRIDGEWAY CAPITAL MANAGEMENT, LLC | 91K | $132K | -3.5% | 1.371% | 0.00% |
| 6 | LPL Financial LLC | 76K | $111K | β | 1.153% | 0.00% |
| 7 | RENAISSANCE TECHNOLOGIES LLC | 49K | $71K | -0.4% | 0.743% | 0.00% |
| 8 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 42K | $61K | +54.6% | 0.639% | 0.00% |
| 9 | GEODE CAPITAL MANAGEMENT, LLC | 33K | $47K | -0.2% | 0.492% | 0.00% |
| 10 | JAMES INVESTMENT RESEARCH INC | 30K | $43K | 0.0% | 0.449% | 0.00% |
| 11 | CITADEL ADVISORS LLC | 29K | $41K | β | 0.431% | 0.00% |
| 12 | VANGUARD FIDUCIARY TRUST CO | 27K | $40K | β | 0.414% | 0.00% |
| 13 | GWM Advisors LLC | 30K | $30K | 0.0% | 0.449% | 0.00% |
| 14 | STATE STREET CORP | 12K | $18K | 0.0% | 0.183% | 0.00% |
| 15 | Empowered Funds, LLC | 12K | $17K | 0.0% | 0.180% | 0.00% |
| 16 | MORGAN STANLEY | 6K | $8K | -7.1% | 0.088% | 0.00% |
| 17 | Tower Research Capital LLC (TRC) | 3K | $4K | +45.2% | 0.042% | 0.00% |
| 18 | UBS Group AG | 200 | $290 | β | 0.003% | 0.00% |
| 19 | JONES FINANCIAL COMPANIES LLLP | 100 | $181 | 0.0% | 0.002% | 0.00% |
| 20 | ROYAL BANK OF CANADA | 69 | $0 | +13.1% | 0.001% | 0.00% |
| 21 | WELLS FARGO & COMPANY/MN | 0 | $0 | β | 0.000% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in AMS β a direct measure of their conviction.
Filings activity in AMS during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 21 | +17% | 26.87% | +7.95 pp | $3M | +42% |
| Q4 2025 | 18 | 18% | 18.92% | 5.60 pp | $2M | 23% |
| Q3 2025 | 22 | +16% | 24.52% | +2.88 pp | $2M | +13% |
| Q2 2025 | 19 | +0.0% | 21.64% | 4.36 pp | $2M | 17% |
| Q1 2025 | 19 | +5.6% | 26.00% | 9.40 pp | $2M | 27% |
| Q4 2024 | 18 | 5.3% | 35.40% | +1.76 pp | $3M | +5.2% |
| Q3 2024 | 19 | 9.5% | 33.64% | 0.39 pp | $3M | 1.2% |
| Q2 2024 | 21 | β | 34.03% | β | $3M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Latest Form 4 transactions by company officers and directors. Insider buys are widely viewed as the highest-conviction signal because executives are risking personal capital.
| Date | Insider | Action | Shares | Price | Value |
|---|---|---|---|---|---|
| Jun 22, 2026 | Stachowiak Raymond C | Buy | 586K | $2.28 | $1.3M |
Quick answers to the most common questions about buying AMS stock.
Based on Q1 2026 13F filings, institutional ownership of American Shared Hospital Services stands at 26.9%, held across 21 reporting institutions.
National Philanthropic Trust is the largest reported institutional holder of AMS, with approximately 410,746 shares worth $0.00B as of Q1 2026.
Yes β 3 widely-followed marquee investors appear among the top 25 institutional holders of AMS, including RENAISSANCE TECHNOLOGIES LLC, SUSQUEHANNA INTERNATIONAL GROUP, LLP, CITADEL ADVISORS LLC.
Our composite Smart Money Score for AMS is 76 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
6 institutions opened new positions in AMS during Q1 2026, while 3 fully exited. 1 added to existing positions and 12 trimmed.
AMS institutional ownership rose by 7.95 percentage points quarter-over-quarter, with a net change of +3 holders.
The top 10 institutions account for 93.7% of all reported 13F value in AMS, and the top 25 account for 100.0%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
American Shared Hospital Services (AMS) Institutional Ownership