Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in PESI held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 1.2M | $12.5M | -2.3% | 6.304% | 0.00% |
| 2 | MAK CAPITAL ONE LLC | 919K | $9.8M | 0.0% | 4.949% | 1.45% |
| 3 | PRESCOTT GROUP CAPITAL MANAGEMENT, L.L.C. | 777K | $8.3M | 0.0% | 4.186% | 0.83% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 759K | $8.1M | — | 4.091% | 0.00% |
| 5 | GEODE CAPITAL MANAGEMENT, LLC | 433K | $4.6M | +2.3% | 2.331% | 0.00% |
| 6 | HEARTLAND ADVISORS INC | 400K | $4.3M | 0.0% | 2.155% | 0.22% |
| 7 | DIAMOND HILL CAPITAL MANAGEMENT INC | 356K | $3.8M | -8.0% | 1.918% | 0.02% |
| 8 | STATE STREET CORP | 336K | $3.6M | +7.5% | 1.808% | 0.00% |
| 9 | Potomac Capital Management, Inc. | 297K | $3.2M | -13.2% | 1.598% | 2.76% |
| 10 | GROUP ONE TRADING, L.P. | 248K | $2.6M | +6050.3% | 1.334% | 0.09% |
| 11 | DIMENSIONAL FUND ADVISORS LP | 164K | $1.8M | -0.6% | 0.882% | 0.00% |
| 12 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 162K | $1.7M | +6.3% | 0.870% | 0.00% |
| 13 | GOLDMAN SACHS GROUP INC | 143K | $1.5M | +98.4% | 0.769% | 0.00% |
| 14 | NORTHERN TRUST CORP | 130K | $1.4M | +4.9% | 0.698% | 0.00% |
| 15 | North Star Investment Management Corp. | 121K | $1.3M | +2639.4% | 0.649% | 0.08% |
| 16 | MYDA Advisors LLC | 120K | $1.3M | +20.0% | 0.646% | 0.36% |
| 17 | VANGUARD FIDUCIARY TRUST CO | 119K | $1.3M | — | 0.642% | 0.00% |
| 18 | VANGUARD PORTFOLIO MANAGEMENT LLC | 100K | $1.1M | — | 0.540% | 0.00% |
| 19 | CITADEL ADVISORS LLC | 85K | $907K | +5.7% | 0.457% | 0.00% |
| 20 | D. E. Shaw & Co., Inc. | 63K | $673K | -34.4% | 0.339% | 0.00% |
| 21 | UBS Group AG | 62K | $664K | +114.3% | 0.334% | 0.00% |
| 22 | Squarepoint Ops LLC | 52K | $555K | +41.0% | 0.280% | 0.00% |
| 23 | Pale Fire Capital SE | 49K | $520K | +12.5% | 0.262% | 0.05% |
| 24 | BANK OF AMERICA CORP /DE/ | 45K | $483K | +3.5% | 0.243% | 0.00% |
| 25 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 44K | $466K | -10.3% | 0.235% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in PESI — a direct measure of their conviction.
Filings activity in PESI during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 82 | +0.0% | 40.17% | 7.86 pp | $82M | 16% |
| Q4 2025 | 82 | +7.9% | 48.03% | +11.96 pp | $98M | +33% |
| Q3 2025 | 76 | +10% | 36.07% | +3.09 pp | $74M | +9.3% |
| Q2 2025 | 69 | 8.0% | 32.98% | +10.66 pp | $67M | +48% |
| Q1 2025 | 75 | +2.7% | 22.32% | 15.35 pp | $46M | 41% |
| Q4 2024 | 73 | +7.4% | 37.67% | +5.12 pp | $77M | +16% |
| Q3 2024 | 68 | +17% | 32.55% | +10.59 pp | $66M | +48% |
| Q2 2024 | 58 | — | 21.96% | — | $45M | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying PESI stock.
Based on Q1 2026 13F filings, institutional ownership of Perma-Fix Environmental Services, Inc. stands at 40.2%, held across 82 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of PESI, with approximately 1,170,303 shares worth $0.01B as of Q1 2026.
Yes — 2 widely-followed marquee investors appear among the top 25 institutional holders of PESI, including SUSQUEHANNA INTERNATIONAL GROUP, LLP, CITADEL ADVISORS LLC.
Our composite Smart Money Score for PESI is 45 out of 100 (Neutral). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
18 institutions opened new positions in PESI during Q1 2026, while 18 fully exited. 10 added to existing positions and 54 trimmed.
PESI institutional ownership fell by 7.86 percentage points quarter-over-quarter, with a net change of +0 holders.
The top 10 institutions account for 74.2% of all reported 13F value in PESI, and the top 25 account for 93.2%.
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.
Perma-Fix Environmental Services, Inc. (PESI) Institutional Ownership