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Institutional Ownership · SEC Form 13F

Who owns Natural Gas Services Group, Inc. (NGS)


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

Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.

149
Institutional holders
11M
Shares held (tracked funds)
83.9%
Of shares outstanding

How the tape is positioned

The tracked-fund tape on NGS is one-sided between 2025-Q4 and 2026-Q1: 56 added or opened and 13 trimmed or exited — on balance accumulating.

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

NGS’s largest tracked holder by dollar value, DIMENSIONAL FUND ADVISORS LP, 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 conviction gap — its largest holder concentrates the name more heavily than the typical one.

Book-share is each fund’s reported value in NGS 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 149 tracked filers holding NGS, 90 increased or opened the position and 52 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.

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 NGS 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 14

  • VANGUARD CAPITAL MANAGEMENT LLC$19M
  • MARSHALL WACE, LLP$4M
  • JANE STREET GROUP, LLC$3M
  • VANGUARD PORTFOLIO MANAGEMENT LLC$3M
  • VANGUARD FIDUCIARY TRUST CO$3M
  • Walleye Capital LLC$2M

Full exits 5

  • VANGUARD GROUP INC$22M
  • Mill Road Capital Management LLC$4M
  • TWO SIGMA ADVISERS, LP$1M
  • Perritt Capital Management Inc$572K
  • Rothschild Wealth LLC$572K

Largest adds

  • TWO SIGMA INVESTMENTS, LP$12M
  • MILLENNIUM MANAGEMENT LLC$5M
  • Phocas Financial Corp.$5M
  • CITADEL ADVISORS LLC$4M
  • MORGAN STANLEY$4M
  • AMERICAN CENTURY COMPANIES INC$3M

Largest trims

  • AWM Investment Company, Inc.$15M
  • AMERIPRISE FINANCIAL INC$5M
  • CANNELL CAPITAL LLC$4M
  • LPL Financial LLC$3M
  • Invesco Ltd.$2M
  • AEGIS FINANCIAL CORP$429K

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
DIMENSIONAL FUND ADVISORS LP trimmed843,797$32M7.4%2026-Q1
BlackRock, Inc. trimmed789,780$30M6.9%2026-Q1
AEGIS FINANCIAL CORP trimmed587,012$22M5.2%2026-Q1
VANGUARD CAPITAL MANAGEMENT LLC new510,995$19M4.5%2026-Q1
WEBER CAPITAL MANAGEMENT LLC /ADV trimmed481,764$18M4.2%2026-Q1
TWO SIGMA INVESTMENTS, LP added365,209$14M3.2%2026-Q1
ROYCE & ASSOCIATES LP trimmed353,316$13M3.1%2026-Q1
AMERICAN CENTURY COMPANIES INC added339,022$13M3.0%2026-Q1
AMERIPRISE FINANCIAL INC trimmed337,571$13M3.0%2026-Q1
Pacific Ridge Capital Partners, LLC trimmed305,374$12M2.7%2026-Q1
First Eagle Investment Management, LLC trimmed287,188$11M2.5%2026-Q1
GEODE CAPITAL MANAGEMENT, LLC added285,813$11M2.5%2026-Q1
MORGAN STANLEY added263,206$10M2.3%2026-Q1
RENAISSANCE TECHNOLOGIES LLC trimmed238,042$9M2.1%2026-Q1
AWM Investment Company, Inc. trimmed214,776$8M1.9%2026-Q1
BRIDGEWAY CAPITAL MANAGEMENT, LLC213,503$8M1.9%2026-Q1
MILLENNIUM MANAGEMENT LLC added212,542$8M1.9%2026-Q1
STATE STREET CORP added198,987$8M1.8%2026-Q1
CITADEL ADVISORS LLC added192,039$7M1.7%2026-Q1
CANNELL CAPITAL LLC trimmed191,681$7M1.7%2026-Q1
Qube Research & Technologies Ltd added182,644$7M1.6%2026-Q1
Russell Investments Group, Ltd. added179,521$7M1.6%2026-Q1
Phocas Financial Corp. added162,465$6M1.4%2026-Q1
RBF Capital, LLC140,000$5M1.2%2026-Q1
MARSHALL WACE, LLP added114,282$4M1.0%2026-Q1
PRUDENTIAL FINANCIAL INC added110,030$4M1.0%2026-Q1
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added97,866$4M0.9%2026-Q1
Empowered Funds, LLC96,149$4M0.8%2026-Q1
BANK OF AMERICA CORP /DE/ added95,881$4M0.8%2026-Q1
Bank of New York Mellon Corp added95,419$4M0.8%2026-Q1
RAYMOND JAMES FINANCIAL INC trimmed85,866$3M0.8%2026-Q1
NORTHERN TRUST CORP added84,632$3M0.7%2026-Q1
BNP PARIBAS FINANCIAL MARKETS added81,657$3M0.7%2026-Q1
CROWN ADVISORS MANAGEMENT, INC.80,000$3M0.7%2026-Q1
JANE STREET GROUP, LLC added79,385$3M0.7%2026-Q1
VANGUARD PORTFOLIO MANAGEMENT LLC new78,916$3M0.7%2026-Q1
VANGUARD FIDUCIARY TRUST CO new74,951$3M0.7%2026-Q1
Connor, Clark & Lunn Investment Management Ltd. added68,418$3M0.6%2026-Q1
Walleye Capital LLC added61,270$2M0.5%2026-Q1
GOLDMAN SACHS GROUP INC added57,034$2M0.5%2026-Q1
JPMORGAN CHASE & CO added54,919$2M0.5%2026-Q1
UBS Group AG added54,761$2M0.5%2026-Q1
Invesco Ltd. trimmed51,766$2M0.5%2026-Q1
SEI INVESTMENTS CO added45,674$2M0.4%2026-Q1
Uniplan Investment Counsel, Inc. new43,638$2M0.4%2026-Q1
RICE HALL JAMES & ASSOCIATES, LLC trimmed43,568$2M0.4%2026-Q1
Trexquant Investment LP added39,865$2M0.4%2026-Q1
D. E. Shaw & Co., Inc. added39,619$1M0.3%2026-Q1
WHITE PINE CAPITAL LLC trimmed38,363$1M0.3%2026-Q1
Point72 Asset Management, L.P. new37,271$1M0.3%2026-Q1
Informed Momentum Co LLC added35,256$1M0.3%2026-Q1
FIRST TRUST ADVISORS LP added35,035$1M0.3%2026-Q1
SIMPLEX TRADING, LLC added33,348$1M0.3%2026-Q1
NEW YORK STATE COMMON RETIREMENT FUND added31,605$1M0.3%2026-Q1
TrueWealth Advisors, LLC trimmed30,550$1M0.3%2026-Q1
Steward Partners Investment Advisory, LLC added29,943$1M0.3%2026-Q1
CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed28,971$1M0.3%2026-Q1
Illumine Investment Management, LLC new27,985$1M0.2%2026-Q1
Calamos Advisors LLC added26,046$983K0.2%2026-Q1
Quadrature Capital Ltd added23,869$901K0.2%2026-Q1
Assenagon Asset Management S.A. trimmed21,662$818K0.2%2026-Q1
STIFEL FINANCIAL CORP trimmed20,089$758K0.2%2026-Q1
Jump Financial, LLC added18,981$716K0.2%2026-Q1
State of Wyoming added18,540$700K0.2%2026-Q1
Creative Planning added18,011$680K0.2%2026-Q1
North Star Investment Management Corp. new17,000$642K0.1%2026-Q1
ACADIAN ASSET MANAGEMENT LLC trimmed16,659$628K0.1%2026-Q1
FMR LLC added15,940$602K0.1%2026-Q1
STRS OHIO added15,800$596K0.1%2026-Q1
AQR CAPITAL MANAGEMENT LLC added15,631$590K0.1%2026-Q1
GSA CAPITAL PARTNERS LLP trimmed15,243$575K0.1%2026-Q1
Nuveen, LLC15,054$568K0.1%2026-Q1
BRASADA CAPITAL MANAGEMENT, LP15,000$567K0.1%2026-Q1
ARTHUR M. COHEN & ASSOCIATES, LLC14,390$538K0.1%2026-Q1
LAZARD ASSET MANAGEMENT LLC added14,177$535K0.1%2026-Q1
Kestra Advisory Services, LLC added13,000$491K0.1%2026-Q1
HRT FINANCIAL LP trimmed12,880$486K0.1%2026-Q1
RHUMBLINE ADVISERS added12,779$482K0.1%2026-Q1
PRINCIPAL FINANCIAL GROUP INC new12,725$480K0.1%2026-Q1
Voleon Capital Management LP new11,338$428K0.1%2026-Q1
STATE OF WISCONSIN INVESTMENT BOARD added11,312$427K0.1%2026-Q1
Boston Partners trimmed11,014$416K0.1%2026-Q1
R Squared Ltd added10,594$400K0.1%2026-Q1
Numerai GP LLC new10,554$398K0.1%2026-Q1
SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed10,335$390K0.1%2026-Q1
Brevan Howard Capital Management LP new10,253$387K0.1%2026-Q1
Squarepoint Ops LLC trimmed10,146$383K0.1%2026-Q1
PDT Partners, LLC trimmed10,075$380K0.1%2026-Q1
FRANKLIN RESOURCES INC trimmed10,058$380K0.1%2026-Q1
VANGUARD GROUP INC added640,540$22M5.0%2025-Q4 stale
Acuitas Investments, LLC added216,700$6M1.4%2025-Q3 stale
Mill Road Capital Management LLC trimmed109,000$4M0.9%2025-Q4 stale
Inspire Investing, LLC added39,094$1M0.3%2025-Q3 stale
TWO SIGMA ADVISERS, LP added32,030$1M0.3%2025-Q4 stale
JACOBS LEVY EQUITY MANAGEMENT, INC22,915$641K0.1%2025-Q3 stale
Rothschild Wealth LLC new17,000$572K0.1%2025-Q4 stale
Perritt Capital Management Inc added17,000$572K0.1%2025-Q4 stale
ExodusPoint Capital Management, LP added14,105$395K0.1%2025-Q3 stale
HighTower Advisors, LLC added14,723$380K0.1%2025-Q2 stale
WELLINGTON MANAGEMENT GROUP LLP trimmed14,347$370K0.1%2025-Q2 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