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Institutional Ownership · SEC Form 13F

Who owns Innospec Inc. (IOSP)


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

265
Institutional holders
24M
Shares held (tracked funds)

How the tape is positioned

61 tracked funds added or opened IOSP while 63 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

IOSP’s largest tracked holder by dollar value, VANGUARD GROUP 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 IOSP more heavily than its largest holder by dollar value does.

Book-share is each fund’s reported value in IOSP 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 265 tracked filers holding IOSP, 150 increased or opened the position and 119 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 IOSP 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 17

  • VANGUARD PORTFOLIO MANAGEMENT LLC$136M
  • VANGUARD CAPITAL MANAGEMENT LLC$81M
  • VANGUARD FIDUCIARY TRUST CO$12M
  • DEPRINCE RACE & ZOLLO INC$5M
  • Penn Capital Management Company, LLC$2M
  • Centiva Capital, LP$2M

Full exits 17

  • VANGUARD GROUP INC$224M
  • WESTWOOD HOLDINGS GROUP INC$38M
  • Medina Value Partners, LLC$29M
  • TWO SIGMA ADVISERS, LP$12M
  • Walleye Capital LLC$8M
  • AlphaQuest LLC$3M

Largest adds

  • TWO SIGMA INVESTMENTS, LP$31M
  • UBS Group AG$30M
  • Assenagon Asset Management S.A.$22M
  • CITADEL ADVISORS LLC$11M
  • Nuveen, LLC$9M
  • ACADIAN ASSET MANAGEMENT LLC$8M

Largest trims

  • BlackRock, Inc.$90M
  • MILLENNIUM MANAGEMENT LLC$36M
  • VICTORY CAPITAL MANAGEMENT INC$10M
  • Allspring Global Investments Holdings, LLC$9M
  • ROYCE & ASSOCIATES LP$4M
  • Western Standard LLC$4M

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. trimmed2,605,126$190M9.2%2026-Q1
Allspring Global Investments Holdings, LLC trimmed2,315,942$170M8.3%2026-Q1
VANGUARD PORTFOLIO MANAGEMENT LLC new1,860,091$136M6.6%2026-Q1
DIMENSIONAL FUND ADVISORS LP added1,242,089$91M4.4%2026-Q1
VANGUARD CAPITAL MANAGEMENT LLC new1,114,598$81M3.9%2026-Q1
STATE STREET CORP added964,335$70M3.4%2026-Q1
VICTORY CAPITAL MANAGEMENT INC trimmed864,994$63M3.1%2026-Q1
Nuveen, LLC added643,248$47M2.3%2026-Q1
GEODE CAPITAL MANAGEMENT, LLC added630,592$46M2.2%2026-Q1
TWO SIGMA INVESTMENTS, LP added593,039$43M2.1%2026-Q1
UBS Group AG added565,911$41M2.0%2026-Q1
GOLDMAN SACHS GROUP INC added492,011$36M1.7%2026-Q1
Assenagon Asset Management S.A. added490,884$36M1.7%2026-Q1
JPMORGAN CHASE & CO added426,050$31M1.5%2026-Q1
Qube Research & Technologies Ltd added406,624$30M1.4%2026-Q1
CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed365,874$27M1.3%2026-Q1
AQR CAPITAL MANAGEMENT LLC added308,284$23M1.1%2026-Q1
BROWN ADVISORY INC trimmed296,465$22M1.0%2026-Q1
GENDELL JEFFREY L added294,504$22M1.0%2026-Q1
BANK OF AMERICA CORP /DE/ trimmed290,766$21M1.0%2026-Q1
D. E. Shaw & Co., Inc. trimmed286,794$21M1.0%2026-Q1
NORTHERN TRUST CORP added284,239$21M1.0%2026-Q1
ROYCE & ASSOCIATES LP trimmed261,336$19M0.9%2026-Q1
MORGAN STANLEY trimmed235,571$17M0.8%2026-Q1
Western Standard LLC trimmed226,833$17M0.8%2026-Q1
CITADEL ADVISORS LLC added220,883$16M0.8%2026-Q1
SEI INVESTMENTS CO added174,121$13M0.6%2026-Q1
Point72 Asset Management, L.P. added166,794$12M0.6%2026-Q1
VANGUARD FIDUCIARY TRUST CO new160,752$12M0.6%2026-Q1
FIRST WILSHIRE SECURITIES MANAGEMENT INC added148,072$11M0.5%2026-Q1
NORGES BANK trimmed105,689$10M0.5%2026-Q1
JANUS HENDERSON GROUP PLC trimmed133,272$10M0.5%2026-Q1
Bank of New York Mellon Corp trimmed131,291$10M0.5%2026-Q1
HRT FINANCIAL LP added125,055$9M0.4%2026-Q1
ACADIAN ASSET MANAGEMENT LLC added122,552$9M0.4%2026-Q1
HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC trimmed120,810$9M0.4%2026-Q1
PRINCIPAL FINANCIAL GROUP INC added120,477$9M0.4%2026-Q1
PANAGORA ASSET MANAGEMENT INC added119,675$9M0.4%2026-Q1
RENAISSANCE TECHNOLOGIES LLC trimmed118,900$9M0.4%2026-Q1
VOLORIDGE INVESTMENT MANAGEMENT, LLC trimmed107,963$8M0.4%2026-Q1
ZWJ INVESTMENT COUNSEL INC added103,787$8M0.4%2026-Q1
TEACHER RETIREMENT SYSTEM OF TEXAS added103,102$8M0.4%2026-Q1
Invesco Ltd. trimmed98,667$7M0.3%2026-Q1
JANE STREET GROUP, LLC trimmed94,506$7M0.3%2026-Q1
ProShare Advisors LLC added89,841$7M0.3%2026-Q1
Public Sector Pension Investment Board added88,694$6M0.3%2026-Q1
MUTUAL OF AMERICA CAPITAL MANAGEMENT LLC trimmed87,463$6M0.3%2026-Q1
Trexquant Investment LP added78,370$6M0.3%2026-Q1
Numerai GP LLC trimmed76,616$6M0.3%2026-Q1
UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed74,443$5M0.3%2026-Q1
Russell Investments Group, Ltd. added71,607$5M0.3%2026-Q1
RHUMBLINE ADVISERS added71,157$5M0.3%2026-Q1
Leeward Investments, LLC - MA trimmed69,810$5M0.2%2026-Q1
DEPRINCE RACE & ZOLLO INC new68,029$5M0.2%2026-Q1
Engineers Gate Manager LP added64,682$5M0.2%2026-Q1
HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND trimmed61,669$5M0.2%2026-Q1
MILLENNIUM MANAGEMENT LLC trimmed61,427$4M0.2%2026-Q1
SG Americas Securities, LLC trimmed60,868$4M0.2%2026-Q1
Legal & General Group Plc trimmed59,120$4M0.2%2026-Q1
AMERIPRISE FINANCIAL INC trimmed56,535$4M0.2%2026-Q1
AMERICAN CENTURY COMPANIES INC added55,234$4M0.2%2026-Q1
FMR LLC added51,805$4M0.2%2026-Q1
Swiss National Bank49,003$4M0.2%2026-Q1
INTECH INVESTMENT MANAGEMENT LLC trimmed44,967$3M0.2%2026-Q1
Atom Investors LP added40,771$3M0.1%2026-Q1
IEQ CAPITAL, LLC added39,960$3M0.1%2026-Q1
BNP PARIBAS FINANCIAL MARKETS added37,967$3M0.1%2026-Q1
Creative Planning trimmed37,635$3M0.1%2026-Q1
XTX Topco Ltd added36,292$3M0.1%2026-Q1
PDT Partners, LLC trimmed34,576$3M0.1%2026-Q1
Edgestream Partners, L.P. trimmed34,226$2M0.1%2026-Q1
MARSHALL WACE, LLP added33,526$2M0.1%2026-Q1
FRANKLIN RESOURCES INC added33,485$2M0.1%2026-Q1
Y-Intercept (Hong Kong) Ltd added33,296$2M0.1%2026-Q1
Penn Capital Management Company, LLC new33,286$2M0.1%2026-Q1
CONNORS INVESTOR SERVICES INC added33,095$2M0.1%2026-Q1
PRICE T ROWE ASSOCIATES INC /MD/ added31,826$2M0.1%2026-Q1
INGALLS & SNYDER LLC28,927$2M0.1%2026-Q1
State of New Jersey Common Pension Fund D trimmed28,227$2M0.1%2026-Q1
ALLIANCEBERNSTEIN L.P. trimmed26,509$2M0.1%2026-Q1
CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added27,529$2M0.1%2026-Q1
Moran Wealth Management, LLC trimmed27,031$2M0.1%2026-Q1
Holocene Advisors, LP added26,473$2M0.1%2026-Q1
Schonfeld Strategic Advisors LLC added26,250$2M0.1%2026-Q1
VANGUARD GROUP INC trimmed2,926,874$224M10.9%2025-Q4 stale
WASATCH ADVISORS LP trimmed528,144$50M2.4%2025-Q1 stale
WESTWOOD HOLDINGS GROUP INC added491,451$38M1.8%2025-Q4 stale
Medina Value Partners, LLC added378,769$29M1.4%2025-Q4 stale
Financial Harvest, LLC new433,843$13M0.6%2025-Q1 stale
TWO SIGMA ADVISERS, LP added159,200$12M0.6%2025-Q4 stale
Cubist Systematic Strategies, LLC trimmed154,165$12M0.6%2025-Q3 stale
SEGALL BRYANT & HAMILL, LLC added118,161$10M0.5%2025-Q2 stale
Walleye Capital LLC trimmed103,935$8M0.4%2025-Q4 stale
KIRR MARBACH & CO LLC /IN/ trimmed54,335$5M0.2%2025-Q2 stale
AlphaQuest LLC trimmed42,228$3M0.2%2025-Q4 stale
ALGERT GLOBAL LLC trimmed34,278$3M0.1%2025-Q4 stale
Nebula Research & Development LLC added28,128$2M0.1%2025-Q2 stale
BAHL & GAYNOR INC added27,306$2M0.1%2025-Q3 stale
Verition Fund Management LLC trimmed26,664$2M0.1%2025-Q4 stale
CANADA PENSION PLAN INVESTMENT BOARD26,000$2M0.1%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