IOSP Institutional Ownership & Shareholders
INNOSPEC INC (IOSP) is currently held by 288 institutional investors tracked by InsiderSet, with a combined reported market value of approximately $2.05B based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of IOSP tracked by InsiderSet, reporting ownership valued at approximately $356.60M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $342.66M, representing an estimated loss of -3.91% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 56% of the total disclosed IOSP value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Vanguard Portfolio Management Llc, Dimensional Fund Advisors Lp, and several other long-term asset managers with concentrated positions in INNOSPEC INC (IOSP).
This page ranks the largest institutional IOSP shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
288
Total Reported Value
$2.05B
Largest Holder
Blackrock, Inc.
Largest Position
$356.60M
Insider Transactions (90d)
0
Latest Filing Quarter
Q2 2026
New Institutional Positions
47
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.01% | 4,381,323 | $356,595,899 | $342,663,272 | -$13,932,627 | -3.91% | |
| Vanguard Portfolio Management Llc | 0.01% | 1,884,244 | $153,358,619 | $147,366,723 | -$5,991,896 | -3.91% | |
| Dimensional Fund Advisors Lp | 0.02% | 1,371,706 | $130,753,831 | $107,281,126 | -$23,472,705 | -17.95% | |
| Allspring Global Investments Holdings, Llc | 0.17% | 1,161,421 | $110,532,437 | $90,834,736 | -$19,697,701 | -17.82% | |
| Vanguard Capital Management Llc | 0.00% | 1,108,107 | $90,188,829 | $86,665,048 | -$3,523,781 | -3.91% | |
| State Street Corp | 0.00% | 996,027 | $81,066,638 | $77,899,272 | -$3,167,366 | -3.91% | |
| Geode Capital Management, Llc | 0.00% | 649,955 | $61,965,934 | $50,832,981 | -$11,132,953 | -17.97% | |
| Nuveen, Llc | 0.01% | 755,723 | $61,508,264 | $59,105,096 | -$2,403,168 | -3.91% | |
| Goldman Sachs Group Inc | 0.01% | 662,210 | $53,897,272 | $51,791,444 | -$2,105,828 | -3.91% | |
| Victory Capital Management Inc | 0.03% | 660,110 | $53,726,353 | $51,627,203 | -$2,099,150 | -3.91% | |
| Two Sigma Investments, Lp | 0.03% | 568,709 | $46,287,226 | $44,478,731 | -$1,808,495 | -3.91% | |
| Aqr Capital Management Llc | 0.01% | 482,545 | $39,274,305 | $37,739,844 | -$1,534,461 | -3.91% | |
| Brown Advisory Inc | 0.05% | 408,468 | $33,245,234 | $31,946,282 | -$1,298,952 | -3.91% | |
| Wasatch Advisors Lp | 0.24% | 335,398 | $31,970,137 | $26,231,478 | -$5,738,659 | -17.95% | |
| Assenagon Asset Management S.A. | 0.03% | 319,633 | $30,467,418 | $24,998,497 | -$5,468,921 | -17.95% | |
| Jpmorgan Chase & Co | 0.00% | 370,574 | $29,998,212 | $28,982,593 | -$1,015,619 | -3.39% | |
| Charles Schwab Investment Management Inc | 0.00% | 355,658 | $28,947,005 | $27,816,012 | -$1,130,993 | -3.91% | |
| Gendell Jeffrey L | 0.24% | 324,504 | $26,411,381 | $25,379,458 | -$1,031,923 | -3.91% | |
| Royce & Associates Lp | 0.20% | 308,726 | $25,127,209 | $24,145,460 | -$981,749 | -3.91% | |
| Northern Trust Corp | 0.00% | 303,044 | $24,664,751 | $23,701,071 | -$963,680 | -3.91% | |
| Qube Research & Technologies Ltd | 0.03% | 285,849 | $23,265,250 | $22,356,250 | -$909,000 | -3.91% | |
| Acadian Asset Management Llc | 0.03% | 273,999 | $22,287,000 | $21,429,462 | -$857,538 | -3.85% | |
| Western Standard Llc | 6.53% | 236,833 | $19,275,838 | $18,522,709 | -$753,129 | -3.91% | |
| Bank Of America Corp | 0.00% | 235,742 | $19,187,042 | $18,437,382 | -$749,660 | -3.91% | |
| Morgan Stanley | 0.00% | 230,793 | $18,784,284 | $18,050,321 | -$733,963 | -3.91% | |
| Renaissance Technologies LLC | Jim Simons | 0.02% | 185,000 | $15,057,150 | $14,468,850 | -$588,300 | -3.91% |
| Panagora Asset Management Inc | 0.05% | 182,538 | $14,856,768 | $14,276,297 | -$580,471 | -3.91% | |
| Principal Financial Group Inc | 0.01% | 144,283 | $13,753,055 | $11,284,373 | -$2,468,682 | -17.95% | |
| Mackenzie Financial Corp | 0.01% | 141,783 | $13,514,756 | $11,088,848 | -$2,425,908 | -17.95% | |
| D. E. Shaw & Co., Inc. | 0.01% | 165,746 | $13,490,067 | $12,962,995 | -$527,072 | -3.91% | |
| Vanguard Fiduciary Trust Co | 0.00% | 163,715 | $13,324,764 | $12,804,150 | -$520,614 | -3.91% | |
| Bank Of New York Mellon Corp | 0.00% | 138,631 | $13,214,341 | $10,842,331 | -$2,372,010 | -17.95% | |
| Sei Investments Co | 0.01% | 156,051 | $12,701,035 | $12,204,749 | -$496,286 | -3.91% | |
| Ubs Group Ag | 0.00% | 154,001 | $12,534,141 | $12,044,418 | -$489,723 | -3.91% | |
| Creative Planning | 0.01% | 131,473 | $12,532,006 | $10,282,503 | -$2,249,503 | -17.95% | |
| First Wilshire Securities Management Inc | 2.47% | 147,112 | $11,973,446 | $11,505,630 | -$467,816 | -3.91% | |
| Proshare Advisors Llc | 0.02% | 118,767 | $11,320,871 | $9,288,767 | -$2,032,104 | -17.95% | |
| Leeward Investments, Llc - Ma | 0.57% | 118,035 | $11,251,096 | $9,231,517 | -$2,019,579 | -17.95% | |
| Hotchkis & Wiley Capital Management Llc | 0.03% | 135,740 | $11,047,879 | $10,616,225 | -$431,654 | -3.91% | |
| Russell Investments Group, Ltd. | 0.01% | 115,475 | $11,030,995 | $9,031,300 | -$1,999,695 | -18.13% | |
| Zwj Investment Counsel Inc | 0.34% | 114,933 | $10,955,218 | $8,988,910 | -$1,966,308 | -17.95% | |
| Janus Henderson Group Plc | 0.00% | 133,272 | $9,732,040 | $10,423,203 | +$691,163 | +7.10% | |
| Invesco Ltd. | 0.00% | 118,427 | $9,638,773 | $9,262,176 | -$376,597 | -3.91% | |
| Deprince Race & Zollo Inc | 0.15% | 89,102 | $8,493,203 | $6,968,667 | -$1,524,536 | -17.95% | |
| Citadel Advisors Llc | 0.00% | 98,549 | $8,020,903 | $7,707,517 | -$313,386 | -3.91% | |
| Mutual Of America Capital Management Llc | 0.08% | 82,548 | $7,868,475 | $6,456,079 | -$1,412,396 | -17.95% | |
| First Trust Advisors Lp | 0.00% | 91,252 | $7,426,999 | $7,136,819 | -$290,180 | -3.91% | |
| Teacher Retirement System Of Texas | 0.02% | 85,463 | $6,955,833 | $6,684,061 | -$271,772 | -3.91% | |
| Public Sector Pension Investment Board | 0.02% | 84,577 | $6,883,722 | $6,614,767 | -$268,955 | -3.91% | |
| Hrt Financial Lp | 0.01% | 84,349 | $6,865,000 | $6,596,935 | -$268,065 | -3.90% |
Frequently asked questions about IOSP
Who are the largest institutional holders of IOSP?
The largest institutional holders of IOSP reported in the latest SEC Form 13F filings include Blackrock, Inc., Vanguard Portfolio Management Llc, Dimensional Fund Advisors Lp, Allspring Global Investments Holdings, Llc, and Vanguard Capital Management Llc. InsiderSet ranks institutional holders by their latest reported IOSP position.
What is IOSP institutional ownership?
This page tracks IOSP positions reported by institutional investment managers through SEC Form 13F. INNOSPEC INC (IOSP) institutional ownership on InsiderSet reflects disclosed 13F holdings among the managers we analyze, not every shareholder of the stock.
How many institutions own IOSP?
InsiderSet currently tracks 288 institutional managers reporting IOSP holdings in the latest available 13F data. This count reflects institutions included in the SEC Form 13F filings analyzed by InsiderSet and should not be interpreted as the total number of IOSP shareholders.
How much IOSP stock do institutions own?
Institutional investment managers disclosed approximately $2.05B in IOSP holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value.
When was IOSP institutional ownership last updated?
The latest IOSP institutional ownership data on InsiderSet is based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time institutional holdings.
Are institutional IOSP holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by institutional investment managers as of the end of the reporting quarter. An institution may have changed its IOSP position after the reporting date.
Are institutions buying or selling IOSP?
Institutional buying and selling can be analyzed by comparing IOSP positions across consecutive 13F reporting periods. InsiderSet's IOSP Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View IOSP ownership changes.
How has IOSP institutional ownership changed over time?
InsiderSet tracks IOSP institutional holdings across multiple 13F reporting periods, allowing investors to compare institutional holder counts, reported value, and reported shares over time.