Perma-Fix Environmental Svcs Inc
Ownership
Ownership Structure
Who owns Perma-Fix Environmental Svcs Inc (PESI)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 93.5% of the shares are freely tradable; institutional investors hold 49.3%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 5.90 | 1,252,756 | +7.0 | 06/30/2026 |
| Mak Capital One LLC | 4.87 | 1,032,958 | +12.4 | 06/30/2026 |
| Vanguard Capital Management, LLC | 3.83 | 811,743 | +6.9 | 06/30/2026 |
| Prescott Group Capital Management LLC | 3.66 | 777,142 | +0.0 | 06/30/2026 |
| Diamond Hill Capital Management, LLC | 3.03 | 642,533 | +80.5 | 06/30/2026 |
| Kennedy Capital Management Inc | 2.88 | 610,903 | +0.0 | 06/30/2026 |
| Potomac Capital Management, Inc. | 2.25 | 477,000 | +60.8 | 06/30/2026 |
| Geode Capital Management, LLC | 2.15 | 455,156 | +5.2 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.82 | 597,751 | +0.0 | 09/30/2026 |
| iShares Russell 2000 ETF | 2.44 | 518,170 | -1.1 | 09/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Zwecker Mark A | Director | 248,644 | 3,108,050 $ | Oct 1, 2026 | direct |
| Reeder Joe | Director | 240,634 | 3,007,925 $ | Oct 1, 2026 | direct |
| Shelton Larry | Director | 200,229 | 2,502,863 $ | Oct 1, 2026 | direct |
| Grumski Joseph Timothy | Director | 69,099 | 863,738 $ | Oct 1, 2026 | direct |
| Wamp Zach Paul | Director | 54,248 | 678,100 $ | Oct 1, 2026 | direct |
| Bostick Thomas | Director | 51,718 | 646,475 $ | Oct 1, 2026 | direct |
| Grondin Richard | EVP of Hanford Waste Ops | 43,744 | 546,800 $ | Oct 28, 2026 | direct |
| Duggan Kerry C | Director | 8,388 | 104,850 $ | Oct 1, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Oct 28, 2026 | Grondin Richard | EVP of Hanford Waste Ops | Other | 2,564 | 13.66 | 35,024 |
| Oct 28, 2026 | Grondin Richard | EVP of Hanford Waste Ops | Other | 5,000 | 7.01 | 35,025 |
| Oct 1, 2026 | Duggan Kerry C | Director | Other | 748 | 11.74 | 8,780 |
| Oct 1, 2026 | Wamp Zach Paul | Director | Other | 775 | 11.74 | 9,097 |
| Oct 1, 2026 | Shelton Larry | Director | Other | 1,246 | 11.74 | 14,625 |
| Oct 1, 2026 | Reeder Joe | Director | Other | 1,289 | 11.74 | 15,130 |
| Oct 1, 2026 | Grumski Joseph Timothy | Director | Other | 1,438 | 11.74 | 16,879 |
| Oct 1, 2026 | Bostick Thomas | Director | Other | 1,108 | 11.74 | 13,005 |
| Oct 1, 2026 | Zwecker Mark A | Director | Other | 1,038 | 11.74 | 12,184 |
| Jul 13, 2026 | Shelton Larry | Director | Other | 2,400 | 4.60 | 11,040 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: October 30, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.