Comparable stake leader
Hold Alapkezelo Zrt.
SEC ownership of PERMA FIX ENVIRONMENTAL SERVICES INC
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0000891532.
Disclosed value leader
Hold Alapkezelo Zrt.
Comparable rows
50/50
Latest evidence
31 Mar 2026
- Public ticker
- PESI on Nasdaq
- Parsed ownership sources
-
13D/G, 3/4/5, and 13F
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
Hold Alapkezelo Zrt.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
Hold Alapkezelo Zrt.
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
31 Mar 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0000891532
- Issuer location
- Atlanta, GA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of PERMA FIX ENVIRONMENTAL SERVICES INC (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
Hold Alapkezelo Zrt.
Disclosed value leader
Hold Alapkezelo Zrt.
Comparable rows
50/50
Latest evidence
31 Mar 2026
13D/G
3/4/5
13F
Lead comparable stake: 5.1%
13D/G row: Hold Alapkezelo Zrt.
Showing 1-8 of 50 holder rows.
Quick read
Hold Alapkezelo Zrt. leads the comparable SEC ownership view at 5.1%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens Hold Alapkezelo Zrt.'s linked filing trail.
Comparable ownership
Top 5
Hold Alapkezelo Zrt.
5.1%
Louis F. Centofanti
1.5%
Mark Duff
0.73%
BlackRock, Inc.
6.3%
MAK CAPITAL ONE LLC
5%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| Hold Alapkezelo Zrt. |
13D/G
|
5.1%
|
$12,672,667
944,312 shares
|
$0 | 31 Mar 2026 |
| Louis F. Centofanti |
3/4/5
EVP of Strategic Initiatives, Director
|
1.5%
|
$3,905,484
280,365 shares
|
— | 17 Nov 2025 |
| Mark Duff |
3/4/5
President and CEO, Director
|
0.73%
|
$1,083,175
134,556 shares
|
+$7,221 | 11 Sep 2025 |
| BlackRock, Inc. |
13F
Company
|
6.3%
|
$12,510,539
1,170,303 shares
|
— | 31 Mar 2026 |
| MAK CAPITAL ONE LLC |
13F
Company
|
5%
|
$9,820,614
918,673 shares
|
— | 31 Mar 2026 |
| PRESCOTT GROUP CAPITAL MANAGEMENT, L.L.C. |
13F
Company
|
4.2%
|
$8,307,648
777,142 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
4.1%
|
$8,118,360
759,435 shares
|
— | 31 Mar 2026 |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
Company
|
2.3%
|
$4,626,994
432,701 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$23,210.
Buys
$25,406
Insiders: 2
Sells
$48,616
Insiders: 1
Net
-$23,210
Shares: -2,756
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 2,897
Shares: 5,653
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 2,897 | 5,653 | $25,406 | $48,616 | -$23,210 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-14 of 14 reporting-owner rows connected to PERMA FIX ENVIRONMENTAL SERVICES INC. Open a relationship link for the CIK-to-CIK filing trail.
Rows
14
Largest Forms 3/4/5 holder
Louis F. Centofanti
Net 12M change
-$23,210
Latest report
22 Jul 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Louis F. Centofanti | EVP of Strategic Initiatives, Director | $3,905,484 | Mixed | 17 Nov 2025 | ||
| Larry Shelton | Director | $2,842,074 | +$18,185 | +0.64% | Median | 22 Jul 2026 |
| Mark A. Zwecker | Director | $2,646,908 | Mixed | 22 Jul 2026 | ||
| Joe Reeder | Director | $2,558,598 | Mixed | 22 Jul 2026 | ||
| Mark Duff | President and CEO, Director | $1,083,175 | +$7,221 | +0.67% | Filing P/S | 11 Sep 2025 |
| Joseph Timothy Grumski | Director | $723,296 | Mixed | 22 Jul 2026 | ||
| Zach Paul Wamp | Director | $571,626 | Mixed | 22 Jul 2026 | ||
| Richard Grondin | EVP of Hanford & Int. Waste Op | $566,332 | Mixed | 20 Jan 2026 | ||
| Thomas P. Bostick | Director | $541,020 | Mixed | 22 Jul 2026 | ||
| Ben Naccarato | Chief Financial Officer | $341,677 | Filing P/S | 21 Mar 2025 | ||
| Andy Lombardo | EVP of Nuclear & Technical Svc | $89,857 | Mixed | 05 Dec 2023 | ||
| Kerry C. Duggan | Director | $81,671 | -$48,616 | -37% | Mixed | 22 Jul 2026 |
| Troy Eshleman | Chief Operating Officer | $9,923 | Filing P/S | 18 Mar 2025 | ||
| William J. Nasgovitz | No Longer Subject to Sec. 16 | Mixed | 17 Sep 2021 |
Recent insider transactions for PERMA FIX ENVIRONMENTAL SERVICES INC
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Joe Reeder | PESI | Stock Option (Right to Buy) | Award | 10,000 | 10,000 | 22 Jul 2026 | Direct | |||
| Zach Paul Wamp | PESI | Stock Option (Right to Buy) | Award | 10,000 | 10,000 | 22 Jul 2026 | Direct | |||
| Larry Shelton | PESI | Stock Option (Right to Buy) | Award | 10,000 | 10,000 | 22 Jul 2026 | Direct | |||
| Mark A. Zwecker | PESI | Stock Option (Right to Buy) | Award | 10,000 | 10,000 | 22 Jul 2026 | Direct | |||
| Thomas P. Bostick | PESI | Stock Option (Right to Buy) | Award | 10,000 | 10,000 | 22 Jul 2026 | Direct | |||
| Joseph Timothy Grumski | PESI | Stock Option (Right to Buy) | Award | 10,000 | 10,000 | 22 Jul 2026 | Direct | |||
| Kerry C. Duggan | PESI | Stock Option (Right to Buy) | Award | 10,000 | 10,000 | 22 Jul 2026 | Direct | |||
| Larry Shelton | PESI | Common Stock | Options Exercise | 1.22% | 2,400 | 198,983 | 13 Jul 2026 | Direct | ||
| Larry Shelton | PESI | Stock Option (Right to Buy) | Options Exercise | -100% | -2,400 | 0 | 13 Jul 2026 | Direct | ||
| Joseph Timothy Grumski | PESI | Common Stock | Award | 2.31% | 1,528 | 67,661 | 01 Jul 2026 | Direct | ||
| Mark A. Zwecker | PESI | Common Stock | Award | 0.47% | 1,167 | 247,606 | 01 Jul 2026 | Direct | ||
| Thomas P. Bostick | PESI | Common Stock | Award | 2.46% | 1,213 | 50,610 | 01 Jul 2026 | Direct | ||
| Joe Reeder | PESI | Common Stock | Award | 0.61% | 1,458 | 239,345 | 01 Jul 2026 | Direct | ||
| Zach Paul Wamp | PESI | Common Stock | Award | 1.61% | 849 | 53,473 | 01 Jul 2026 | Direct | ||
| Larry Shelton | PESI | Common Stock | Award | 0.7% | 1,365 | 196,583 | 01 Jul 2026 | Direct | ||
| Kerry C. Duggan | PESI | Common Stock | Award | 12% | 819 | 7,640 | 01 Jul 2026 | Direct | ||
| Mark A. Zwecker | PESI | Common Stock | Award | 0.63% | 1,520 | 244,039 | 01 Apr 2026 | Direct | ||
| Joe Reeder | PESI | Common Stock | Award | 0.8% | 1,886 | 237,887 | 01 Apr 2026 | Direct | ||
| Kerry C. Duggan | PESI | Common Stock | Award | 18.3% | 1,054 | 6,821 | 01 Apr 2026 | Direct | ||
| Joseph Timothy Grumski | PESI | Common Stock | Award | 3.29% | 2,105 | 66,133 | 01 Apr 2026 | Direct | ||
| Thomas P. Bostick | PESI | Common Stock | Award | 3.26% | 1,559 | 49,397 | 01 Apr 2026 | Direct | ||
| Zach Paul Wamp | PESI | Common Stock | Award | 2.12% | 1,094 | 52,624 | 01 Apr 2026 | Direct | ||
| Larry Shelton | PESI | Common Stock | Award | 0.94% | 1,824 | 195,218 | 01 Apr 2026 | Direct | ||
| Richard Grondin | PESI | Common Stock | Tax liability | -10.4% | -4,284 | 37,037 | 20 Jan 2026 | Direct | ||
| Richard Grondin | PESI | Common Stock | Options Exercise | 34.3% | 11,000 | 43,037 | 20 Jan 2026 | Direct | ||
| Richard Grondin | PESI | Stock Option | Options Exercise | -68.8% | -11,000 | 5,000 | 20 Jan 2026 | Direct | ||
| Joe Reeder | PESI | Common Stock | Award | 0.66% | 1,549 | 236,001 | 02 Jan 2026 | Direct | ||
| Thomas P. Bostick | PESI | Common Stock | Award | 2.85% | 1,324 | 47,838 | 02 Jan 2026 | Direct | ||
| Zach Paul Wamp | PESI | Common Stock | Award | 1.91% | 964 | 51,530 | 02 Jan 2026 | Direct | ||
| Joseph Timothy Grumski | PESI | Common Stock | Award | 2.96% | 1,840 | 64,028 | 02 Jan 2026 | Direct | ||
| Kerry C. Duggan | PESI | Common Stock | Award | 19.2% | 929 | 5,767 | 02 Jan 2026 | Direct | ||
| Larry Shelton | PESI | Common Stock | Award | 0.83% | 1,583 | 193,394 | 02 Jan 2026 | Direct | ||
| Mark A. Zwecker | PESI | Common Stock | Award | 0.55% | 1,325 | 242,519 | 02 Jan 2026 | Direct | ||
| Joe Reeder | PESI | Common Stock | Gift | -5.62% | -13,956 | 234,452 | 15 Dec 2025 | Direct | ||
| Louis F. Centofanti | PESI | Common Stock | Gift | -0.55% | -1,200 | 217,565 | 17 Nov 2025 | Direct | ||
| Thomas P. Bostick | PESI | Common Stock | Award | 3.83% | 1,716 | 46,514 | 01 Oct 2025 | Direct | ||
| Joseph Timothy Grumski | PESI | Common Stock | Award | 3.72% | 2,228 | 62,188 | 01 Oct 2025 | Direct | ||
| Mark A. Zwecker | PESI | Common Stock | Award | 0.67% | 1,609 | 241,194 | 01 Oct 2025 | Direct | ||
| Zach Paul Wamp | PESI | Common Stock | Award | 2.43% | 1,201 | 50,566 | 01 Oct 2025 | Direct | ||
| Larry Shelton | PESI | Common Stock | Award | 1.02% | 1,931 | 191,811 | 01 Oct 2025 | Direct | ||
| Joe Reeder | PESI | Common Stock | Award | 0.84% | 2,063 | 248,408 | 01 Oct 2025 | Direct | ||
| Kerry C. Duggan | PESI | Common Stock | Award | 31.5% | 1,158 | 4,838 | 01 Oct 2025 | Direct | ||
| Kerry C. Duggan | PESI | Common Stock | Sale | -60.6% | $48,616 | $8.60 | -5,653 | 3,680 | 16 Sep 2025 | Direct |
| Mark Duff | PESI | Common Stock | Purchase | 0.67% | $7,221 | $8.05 | 897 | 134,556 | 11 Sep 2025 | Direct |
| Larry Shelton | PESI | Common Stock | Purchase | 0.53% | $8,575 | $8.58 | 1,000 | 189,880 | 11 Sep 2025 | Direct |
| Larry Shelton | PESI | Common Stock | Purchase | 0.53% | $9,610 | $9.61 | 1,000 | 188,880 | 09 Sep 2025 | Direct |
| Larry Shelton | PESI | Common Stock | Options Exercise | 1.29% | 2,400 | 187,880 | 02 Sep 2025 | Direct | ||
| Larry Shelton | PESI | Stock Option (Right to Buy) | Options Exercise | -100% | -2,400 | 0 | 02 Sep 2025 | Direct | ||
| Mark A. Zwecker | PESI | Common Stock | Options Exercise | 1.01% | 2,400 | 239,585 | 28 Aug 2025 | Direct | ||
| Mark A. Zwecker | PESI | Stock Option (Right to Buy) | Options Exercise | -100% | -2,400 | 0 | 28 Aug 2025 | Direct |
* marks a reported price that did not pass the local price check.