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Institutional Ownership · SEC Form 13F

Who owns Perma-Fix Environmental Services, Inc. (PESI)


Which tracked institutional funds hold PESI, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See PESI company fundamentals →

Ownership as of the 2026-Q1 13F filings. 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.

85
Institutional holders
8M
Shares held (tracked funds)
40.9%
Of shares outstanding

How the tape is positioned

8 tracked funds added or opened PESI while 20 trimmed or exited it between 2025-Q4 and 2026-Q1 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.

A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.

Conviction spread

PESI’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes PESI more heavily than its largest holder by dollar value does.

Book-share is each fund’s reported value in PESI divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.

Institutional & insider positioning

Between 2025-Q4 and 2026-Q1, across 85 tracked filers holding PESI, 37 increased or opened the position and 42 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.

This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.

New buyers & exits

Funds opening or closing a position in PESI between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.

New buyers 3

  • VANGUARD CAPITAL MANAGEMENT LLC$8M
  • VANGUARD FIDUCIARY TRUST CO$1M
  • VANGUARD PORTFOLIO MANAGEMENT LLC$1M

Full exits 4

  • VANGUARD GROUP INC$12M
  • Perritt Capital Management Inc$2M
  • Informed Momentum Co LLC$816K
  • Ancora Advisors LLC$729K

Largest adds

  • GROUP ONE TRADING LLC$3M
  • North Star Investment Management Corp.$1M
  • GOLDMAN SACHS GROUP INC$620K
  • UBS Group AG$299K
  • CITADEL ADVISORS LLC$286K

Largest trims

  • BlackRock, Inc.$3M
  • Rothschild Wealth LLC$2M
  • MAK CAPITAL ONE LLC$2M
  • JANE STREET GROUP, LLC$2M
  • Prescott Group Capital Management, L.L.C.$1M
  • Potomac Capital Management, Inc.$1M

Institutional holders

One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).

FundSharesReported value% of valueQuarter
BlackRock, Inc. trimmed1,170,303$13M11.6%2026-Q1
MAK CAPITAL ONE LLC918,673$10M9.1%2026-Q1
Prescott Group Capital Management, L.L.C.777,142$8M7.7%2026-Q1
VANGUARD CAPITAL MANAGEMENT LLC new759,435$8M7.5%2026-Q1
GEODE CAPITAL MANAGEMENT, LLC added432,701$5M4.3%2026-Q1
HEARTLAND ADVISORS INC400,000$4M4.0%2026-Q1
DIAMOND HILL CAPITAL MANAGEMENT INC trimmed355,978$4M3.5%2026-Q1
STATE STREET CORP added335,547$4M3.3%2026-Q1
Potomac Capital Management, Inc. trimmed296,700$3M2.9%2026-Q1
GROUP ONE TRADING LLC added247,674$3M2.4%2026-Q1
DIMENSIONAL FUND ADVISORS LP trimmed163,787$2M1.6%2026-Q1
GOLDMAN SACHS GROUP INC added142,687$2M1.4%2026-Q1
NORTHERN TRUST CORP added129,568$1M1.3%2026-Q1
North Star Investment Management Corp. added120,532$1M1.2%2026-Q1
MYDA Advisors LLC added120,000$1M1.2%2026-Q1
VANGUARD FIDUCIARY TRUST CO new119,253$1M1.2%2026-Q1
VANGUARD PORTFOLIO MANAGEMENT LLC new100,318$1M1.0%2026-Q1
CITADEL ADVISORS LLC added69,313$741K0.7%2026-Q1
D. E. Shaw & Co., Inc. trimmed62,989$673K0.6%2026-Q1
UBS Group AG added62,082$664K0.6%2026-Q1
Squarepoint Ops LLC added51,940$555K0.5%2026-Q1
Pale Fire Capital SE added48,626$520K0.5%2026-Q1
BANK OF AMERICA CORP /DE/ added45,190$483K0.4%2026-Q1
CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed43,590$466K0.4%2026-Q1
Bank of New York Mellon Corp trimmed40,379$432K0.4%2026-Q1
CORSAIR CAPITAL MANAGEMENT, L.P. added37,649$402K0.4%2026-Q1
SIMPLEX TRADING, LLC added31,318$335K0.3%2026-Q1
GatePass Capital, LLC trimmed29,742$318K0.3%2026-Q1
JANE STREET GROUP, LLC trimmed28,525$305K0.3%2026-Q1
MORGAN STANLEY trimmed26,718$286K0.3%2026-Q1
XTX Topco Ltd added23,227$248K0.2%2026-Q1
Nuveen, LLC22,454$240K0.2%2026-Q1
RHUMBLINE ADVISERS trimmed21,410$229K0.2%2026-Q1
WELLS FARGO & COMPANY/MN trimmed20,830$223K0.2%2026-Q1
Rothschild Wealth LLC trimmed20,600$220K0.2%2026-Q1
BROWN ADVISORY INC new20,000$214K0.2%2026-Q1
GUIDANCE CAPITAL, INC trimmed16,302$211K0.2%2026-Q1
BAILARD, INC.17,800$190K0.2%2026-Q1
Oxler Private Wealth LLC17,005$182K0.2%2026-Q1
IMC-Chicago, LLC new16,933$181K0.2%2026-Q1
Quent Capital, LLC16,199$173K0.2%2026-Q1
GSA CAPITAL PARTNERS LLP new16,097$172K0.2%2026-Q1
OSAIC HOLDINGS, INC. added16,000$171K0.2%2026-Q1
DEUTSCHE BANK AG\ added14,621$156K0.1%2026-Q1
Fermata Advisors, LLC added12,936$138K0.1%2026-Q1
Greenhaven Road Investment Management, L.P. added11,303$120K0.1%2026-Q1
PRICE T ROWE ASSOCIATES INC /MD/11,202$120K0.1%2026-Q1
Invesco Ltd. trimmed11,135$119K0.1%2026-Q1
SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed11,098$119K0.1%2026-Q1
AMERICAN CENTURY COMPANIES INC new10,692$114K0.1%2026-Q1
Vident Advisory, LLC new10,390$111K0.1%2026-Q1
MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added8,223$88K0.1%2026-Q1
JPMORGAN CHASE & CO trimmed7,082$74K0.1%2026-Q1
Vanguard Global Advisers, LLC new5,742$61K0.1%2026-Q1
Police & Firemen's Retirement System of New Jersey5,649$60K0.1%2026-Q1
Capital Advisors, Ltd. LLC new5,000$53K0.0%2026-Q1
MetLife Investment Management, LLC trimmed4,922$53K0.0%2026-Q1
FMR LLC trimmed4,726$51K0.0%2026-Q1
NEW YORK STATE COMMON RETIREMENT FUND4,400$47K0.0%2026-Q1
BNP PARIBAS FINANCIAL MARKETS trimmed3,669$39K0.0%2026-Q1
BARCLAYS PLC trimmed3,273$35K0.0%2026-Q1
Russell Investments Group, Ltd. added1,732$19K0.0%2026-Q1
Legal & General Group Plc trimmed1,558$17K0.0%2026-Q1
Tower Research Capital LLC (TRC) trimmed1,528$16K0.0%2026-Q1
Ameritas Investment Partners, Inc.1,232$13K0.0%2026-Q1
CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM trimmed936$10K0.0%2026-Q1
CITIGROUP INC added819$9K0.0%2026-Q1
Sterling Capital Management LLC trimmed501$5K0.0%2026-Q1
VANGUARD GROUP INC added968,107$12M11.3%2025-Q4 stale
VAN ECK ASSOCIATES CORP added220,289$2M2.1%2025-Q3 stale
Perritt Capital Management Inc trimmed166,300$2M1.9%2025-Q4 stale
ESSEX INVESTMENT MANAGEMENT CO LLC added196,197$2M1.8%2025-Q3 stale
Alyeska Investment Group, L.P. trimmed147,417$1M1.0%2025-Q1 stale
Informed Momentum Co LLC trimmed64,784$816K0.8%2025-Q4 stale
THOMPSON SIEGEL & WALMSLEY LLC trimmed104,778$762K0.7%2025-Q1 stale
Ancora Advisors LLC trimmed57,927$729K0.7%2025-Q4 stale
Legato Capital Management LLC56,459$570K0.5%2025-Q3 stale
SEI INVESTMENTS CO new39,442$497K0.5%2025-Q4 stale
MILLENNIUM MANAGEMENT LLC added38,617$486K0.4%2025-Q4 stale
ARS Investment Partners, LLC trimmed36,145$455K0.4%2025-Q4 stale
Trexquant Investment LP added42,156$426K0.4%2025-Q3 stale
LOS ANGELES CAPITAL MANAGEMENT LLC new22,960$322K0.3%2025-Q4 stale
CW Advisors, LLC added30,500$321K0.3%2025-Q2 stale
COMMONS CAPITAL, LLC30,350$319K0.3%2025-Q2 stale
MOODY NATIONAL BANK TRUST DIVISION25,000$263K0.2%2025-Q2 stale
Brookwood Investment Group LLC added20,873$263K0.2%2025-Q4 stale
BRIDGEWAY CAPITAL MANAGEMENT, LLC20,300$214K0.2%2025-Q2 stale
BLUE SQUARE ASSET MANAGEMENT, LLC new20,100$203K0.2%2025-Q3 stale
MARSHALL WACE, LLP added18,405$194K0.2%2025-Q2 stale
HRT FINANCIAL LP trimmed14,585$183K0.2%2025-Q4 stale
Verition Fund Management LLC new14,456$146K0.1%2025-Q3 stale
THOMPSON DAVIS & CO., INC. trimmed13,440$98K0.1%2025-Q1 stale
RENAISSANCE TECHNOLOGIES LLC trimmed11,474$83K0.1%2025-Q1 stale
OPPENHEIMER & CO INC trimmed10,950$80K0.1%2025-Q1 stale
Cubist Systematic Strategies, LLC trimmed10,569$77K0.1%2025-Q1 stale
Corebridge Financial, Inc. added8,284$60K0.1%2025-Q1 stale
RAYMOND JAMES FINANCIAL INC new1,160$12K0.0%2025-Q2 stale
FLAGSHIP HARBOR ADVISORS, LLC new910$11K0.0%2025-Q4 stale
AMALGAMATED BANK trimmed544$7K0.0%2025-Q4 stale
Global Retirement Partners, LLC new500$6K0.0%2025-Q4 stale

Ownership over time

Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.

HoldersTotal shares

Reading this table

Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.

About 13F filings

A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.

Learn how to read institutional ownership