Perma-Fix Environmental Services
PESI
85 hedge funds and large institutions have $80.9M invested in Perma-Fix Environmental Services in 2026 Q1 according to their latest regulatory filings, with 17 funds opening new positions, 20 increasing their positions, 26 reducing their positions, and 13 closing their positions.
31% more first-time investments, than exits
New positions opened: 17 | Existing positions closed: 13
1% more funds holding
Funds holding: 84 → 85 (+1)
1.73% less ownership
Funds ownership: 42.53% → 40.81% (-1.7%)
18% less capital invested
Capital invested by funds: $99.2M → $80.9M (-$18.3M)
23% less repeat investments, than reductions
Existing positions increased: 20 | Existing positions reduced: 26
50% less funds holding in top 10
Funds holding in top 10: 2 → 1 (-1)
73% less call options, than puts
Call options by funds: $1.31M | Put options by funds: $4.85M
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Group One Trading
Chicago,
Illinois
|
+$3.35M |
| 2 |
NSIM
North Star Investment Management
Chicago,
Illinois
|
+$1.6M |
| 3 |
Goldman Sachs
New York
|
+$973K |
| 4 |
Citadel Advisors
Miami,
Florida
|
+$456K |
| 5 |
UBS Group
Zurich,
Switzerland
|
+$455K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
SL
Sentinus LLC
Oak Brook,
Illinois
|
-$2M |
| 2 |
Jane Street
New York
|
-$1.59M |
| 3 |
Susquehanna International Group
Bala Cynwyd,
Pennsylvania
|
-$1.2M |
| 4 |
EI
EAM Investors
Solana Beach,
California
|
-$816K |
| 5 |
AA
Ancora Advisors
Cleveland,
Ohio
|
-$729K |
PESI Hedge Fund Activity: Q1 2026 in Review
85 of the 8,126 institutional investors tracked by Wall St. Rank reported a position in Perma-Fix Environmental Services (PESI) for Q1 2026, worth a combined $80.9M — down 18% from $99.2M a quarter earlier.
Buyers outnumbered sellers: 17 funds opened new PESI positions and 13 closed out — a net gain of 4 holders — while 20 added to existing stakes and 26 trimmed.
The largest buyer was Group One Trading, adding an estimated $3.35M. The largest seller was Sentinus LLC, cutting an estimated $2M.
- 85 institutional investors held Perma-Fix Environmental Services (PESI) as of Q1 2026, up from 84 in Q4 2025.
- Funds reported $80.9M of Perma-Fix Environmental Services stock for Q1 2026, down 18% quarter-over-quarter.
- 17 funds opened new Perma-Fix Environmental Services positions in Q1 2026 and 13 closed out, a net change of +4 holders.
- The largest Perma-Fix Environmental Services buyer in Q1 2026 was Group One Trading, an estimated $3.35M added.
- The largest Perma-Fix Environmental Services seller in Q1 2026 was Sentinus LLC, an estimated $2M sold.
Based on aggregated 13F filings for Q1 2026.