Perma Fix Environmental Services PESI Institutional Ownership

NASDAQ PESI

$12.31 -0.16 (-1.28%)

At close: Oct 22, 2026 · 4:00 PM EDT

Institutions by Trading Activity

90 Institutions

Increased 50 55.6%

Unchanged 23 25.6%

Reduced 17 18.9%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

44.66%

▲+3.85 pp QoQ

Shares Held by Institutions

9.47Mn

of 21.21Mn outstanding

▲+25.13% QoQ

Shares Outstanding

21.21Mn

11.74Mn held outside 13F filers

Institutional Investors

filed 13F for Jun 2026

▲+5 vs prior quarter

Net Shares Added (QoQ)

+1.90Mn

accumulated since last quarter

Value of Holdings

$116.59Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 10, 2026

Perma Fix Environmental Services Inc (NASDAQ:PESI) had 90 institutional holders reporting a position on Form 13F for the quarter ended June 30, 2026.

Their combined stake equaled 44.66% of outstanding shares in Q2 2026, up from 40.81% in Q1 2026.
Total holdings of Perma Fix Environmental Services shares rose 25.13% from Q1 2026, and the number of holders rose 36.36% from Q2 2025.
Of the 90 holders of PESI in Q2 2026, 50 added to their positions, 17 reduced their stakes and 23 left their positions unchanged.
Institutional investors held 9.47Mn shares of Perma Fix Environmental Services in total at the end of Q2 2026, up 1.9Mn from the prior quarter and up 2.88Mn from a year earlier.
As of June 30, 2026, the biggest holder of Perma Fix Environmental Services was BlackRock, Inc. with 1.25Mn shares, or 5.91% of shares outstanding.
The largest position increases in PESI for Q2 2026 were by Diamond Hill Capital Management, LLC (+286.56K shares), Potomac Capital Management, Inc. (+180.3K shares), Susquehanna International Group, LLP (+145.84K shares), Mak Capital One LLC (+114.28K shares) and Citadel Advisors LLC (+83.31K shares).
The largest position reductions in PESI for Q2 2026 were by Group One Trading LLC (-125.06K shares), D. E. Shaw & Co., Inc. (-38.13K shares), UBS Group AG (-30.59K shares), MYDA Advisors LLC (-30K shares) and Squarepoint Ops LLC (-20.96K shares).
Perma Fix Environmental Services' 10 largest institutional shareholders as of Q2 2026 were BlackRock, Inc. (1.25Mn shares), Mak Capital One LLC (1.03Mn shares), Vanguard Capital Management LLC (811.74K shares), Prescott Group Capital Management, L.L.C. (777.14K shares), Diamond Hill Capital Management, LLC (642.53K shares), Kennedy Capital Management LLC (610.9K shares), Potomac Capital Management, Inc. (477K shares), Geode Capital Management, LLC (455.16K shares), Heartland Advisors Inc (400K shares) and State Street Corp (349.74K shares), per Business Quant data.

Form 13F Holdings

90 Institutional Holders

Report period 30 Jun, 2026

Total shares held 9.47Mn

Of outstanding 44.66%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	BlackRock, Inc.	0002012383	1,252,756	5.91%	▲82,453	+7.05%	$17.90Mn
2	MAK CAPITAL ONE LLC	0001385702	1,032,958	4.87%	▲114,285	+12.44%	$14.76Mn
3	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	811,743	3.83%	▲52,308	+6.89%	$11.60Mn
4	PRESCOTT GROUP CAPITAL MANAGEMENT, L.L.C.	0001166152	777,142	3.66%	0	0.00%	$11.11Mn
5	Diamond Hill Capital Management, LLC (Investment Advisor)	0001217541	642,533	3.03%	▲286,555	+80.50%	$9.18Mn
6	KENNEDY CAPITAL MANAGEMENT LLC	0000884589	610,903	2.88%	▲610,903	0.00%	$8.73Mn
7	Potomac Capital Management, Inc.	0001418746	477,000	2.25%	▲180,300	+60.77%	$6.82Mn
8	GEODE CAPITAL MANAGEMENT, LLC	0001214717	455,156	2.15%	▲22,455	+5.19%	$6.51Mn
9	HEARTLAND ADVISORS INC	0000937394	400,000	1.89%	0	0.00%	$5.72Mn
10	State Street Corp	0000093751	349,744	1.65%	▲14,197	+4.23%	$5.00Mn
11	DIMENSIONAL FUND ADVISORS LP	0000354204	191,063	0.90%	▲27,276	+16.65%	$2.73Mn
12	Goldman Sachs Group Inc	0000886982	162,755	0.77%	▲20,068	+14.06%	$2.33Mn
13	SUSQUEHANNA INTERNATIONAL GROUP, LLP	0001446194	156,934	0.74%	▲145,836	+1,314.07%	$2.24Mn
14	CITADEL ADVISORS LLC	0001423053	152,626	0.72%	▲83,313	+120.20%	$2.18Mn
15	Northern Trust Corp	0000073124	141,639	0.67%	▲12,071	+9.32%	$2.02Mn
16	VANGUARD FIDUCIARY TRUST CO	0000933478	123,040	0.58%	▲3,787	+3.18%	$1.76Mn
17	GROUP ONE TRADING LLC	0000932540	122,611	0.58%	▼125,063	-50.50%	$1.75Mn
18	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	121,267	0.57%	▲20,949	+20.88%	$1.73Mn
19	North Star Investment Management Corp.	0001342857	120,532	0.57%	0	0.00%	$1.72Mn
20	Diametric Capital, LP	0001719087	114,714	0.54%	▲114,714	0.00%	$1.64Mn

Showing 1 to 20 of 90 holders