Perma Fix Environmental Services PESI Institutional Ownership

NASDAQ PESI

$17.30 +0.42 (+2.49%)

At close: Aug 21, 2026 · 4:00 PM EDT

Institutions by Trading Activity

84 Institutions

Increased 38 45.2%

Unchanged 18 21.4%

Reduced 28 33.3%

Ownership Statistics

13F · as of 31 Mar, 2026

Institutional Ownership

40.82%

▼-2.17 pp QoQ

Shares Held by Institutions

7.57Mn

of 18.54Mn outstanding

▲+16.34% QoQ

Shares Outstanding

18.54Mn

10.97Mn held outside 13F filers

Institutional Investors

filed 13F for Mar 2026

▲+3 vs prior quarter

Net Shares Added (QoQ)

+1.06Mn

accumulated since last quarter

Value of Holdings

$131.25Mn

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

Quarter ending 31 Mar, 2026

Perma Fix Environmental Services Inc (NASDAQ:PESI) is held by 84 institutional investors per 13F filings through March 2026.

Collectively, these holders controlled 40.8% of Perma Fix Environmental Services's outstanding shares in March 2026, down from 43.0% in December 2025.
They increased total shares held in Perma Fix Environmental Services by 16.34% from last quarter, and the number of investors in PESI increased 9.09% annually.
Activity in PESI broke down as 38 buyers, 28 sellers, and 18 unchanged among 84 total holders.
Institutional investors collectively held 7.57Mn shares in Perma Fix Environmental Services as of March 2026, up by 1.06Mn shares quarter on quarter, and up 604.69K shares year over year.
BlackRock, Inc. holds the largest position in PESI at 1.17Mn shares as of March 31, 2026, or 6.31% of shares outstanding.
Leading buyers of Perma Fix Environmental Services shares for the quarter ending March 2026 were VANGUARD CAPITAL MANAGEMENT LLC (759.44K), GROUP ONE TRADING LLC (243.65K), VANGUARD FIDUCIARY TRUST CO (119.25K), North Star Investment Management Corp. (116.13K), VANGUARD PORTFOLIO MANAGEMENT LLC (100.32K).
The largest sellers of Perma Fix Environmental Services for the quarter ending March 2026 were Rothschild Wealth LLC (145.7K), JANE STREET GROUP, LLC (115.71K), SUSQUEHANNA INTERNATIONAL GROUP, LLP (87.17K), Potomac Capital Management, Inc. (45.1K), Morgan Stanley (40.01K).
Per Business Quant data, the top 10 holders of Perma Fix Environmental Services for the quarter ending March 2026 are BlackRock, Inc. (1.17Mn), MAK CAPITAL ONE LLC (918.67K), PRESCOTT GROUP CAPITAL MANAGEMENT, L.L.C. (777.14K), VANGUARD CAPITAL MANAGEMENT LLC (759.44K), GEODE CAPITAL MANAGEMENT, LLC (432.7K), HEARTLAND ADVISORS INC (400.0K), DIAMOND HILL CAPITAL MANAGEMENT INC (355.98K), State Street Corp (335.55K), Potomac Capital Management, Inc. (296.7K), GROUP ONE TRADING LLC (247.67K).

Form 13F Holdings

84 Institutional Holders

Report period 31 Mar, 2026

Total shares held 7.57Mn

Of outstanding 40.82%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	BlackRock, Inc.	0002012383	1,170,303	6.31%	▼27,682	-2.31%	$12.51Mn
2	MAK CAPITAL ONE LLC	0001385702	918,673	4.95%	0	0.00%	$9.82Mn
3	PRESCOTT GROUP CAPITAL MANAGEMENT, L.L.C.	0001166152	777,142	4.19%	0	0.00%	$8.31Mn
4	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	759,435	4.10%	▲759,435	0.00%	$8.12Mn
5	GEODE CAPITAL MANAGEMENT, LLC	0001214717	432,701	2.33%	▲9,811	+2.32%	$4.63Mn
6	HEARTLAND ADVISORS INC	0000937394	400,000	2.16%	0	0.00%	$4.28Mn
7	DIAMOND HILL CAPITAL MANAGEMENT INC	0001217541	355,978	1.92%	▼30,865	-7.98%	$3.81Mn
8	State Street Corp	0000093751	335,547	1.81%	▲23,280	+7.46%	$3.59Mn
9	Potomac Capital Management, Inc.	0001418746	296,700	1.60%	▼45,100	-13.19%	$3.17Mn
10	GROUP ONE TRADING LLC	0000932540	247,674	1.34%	▲243,647	+6,050.34%	$2.65Mn
11	DIMENSIONAL FUND ADVISORS LP	0000354204	163,787	0.88%	▼1,000	-0.61%	$1.75Mn
12	Goldman Sachs Group Inc	0000886982	142,687	0.77%	▼1,187	-0.83%	$1.53Mn
13	Northern Trust Corp	0000073124	129,568	0.70%	▲6,059	+4.91%	$1.39Mn
14	North Star Investment Management Corp.	0001342857	120,532	0.65%	▲116,132	+2,639.36%	$1.29Mn
15	MYDA Advisors LLC	0001589689	120,000	0.65%	▲20,000	+20.00%	$1.28Mn
16	VANGUARD FIDUCIARY TRUST CO	0000933478	119,253	0.64%	▲119,253	0.00%	$1.27Mn
17	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	100,318	0.54%	▲100,318	0.00%	$1.07Mn
18	CITADEL ADVISORS LLC	0001423053	69,313	0.37%	▲33,184	+91.85%	$740.96K
19	D. E. Shaw & Co., Inc.	0001009207	62,989	0.34%	▼33,020	-34.39%	$673.35K
20	UBS Group AG	0001610520	62,082	0.33%	▲33,118	+114.34%	$663.66K

Showing 1 to 20 of 84 holders