INNOSPEC INC (IOSP) Institutional Shareholders
INNOSPEC INC (IOSP) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026. The institutional investors covered on this page collectively reported approximately $1.99B in IOSP holdings during the latest filing period.
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 $423.24M, representing an estimated gain of +18.69% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 59% of the total disclosed IOSP value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Allspring Global Investments Holdings, Llc, Vanguard Portfolio Management Llc, 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
270
Total Reported Value
$1.99B
Largest Holder
Blackrock, Inc.
Largest Position
$356.60M
Insider Transactions (90d)
0
Latest Filing Quarter
Q2 2026
New Institutional Positions
53
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 | $423,235,802 | +$66,639,903 | +18.69% | |
| Allspring Global Investments Holdings, Llc | 0.24% | 1,892,471 | $154,747,354 | $182,812,699 | +$28,065,345 | +18.14% | |
| Vanguard Portfolio Management Llc | 0.01% | 1,884,244 | $153,358,619 | $182,017,970 | +$28,659,351 | +18.69% | |
| Dimensional Fund Advisors Lp | 0.02% | 1,305,038 | $106,215,943 | $126,066,671 | +$19,850,728 | +18.69% | |
| Vanguard Capital Management Llc | 0.00% | 1,108,107 | $90,188,829 | $107,043,136 | +$16,854,307 | +18.69% | |
| State Street Corp | 0.00% | 996,027 | $81,066,638 | $96,216,208 | +$15,149,570 | +18.69% | |
| Nuveen, Llc | 0.01% | 755,723 | $61,508,264 | $73,002,842 | +$11,494,578 | +18.69% | |
| Geode Capital Management, Llc | 0.00% | 666,589 | $54,263,961 | $64,392,497 | +$10,128,536 | +18.67% | |
| Goldman Sachs Group Inc | 0.01% | 662,210 | $53,897,272 | $63,969,486 | +$10,072,214 | +18.69% | |
| Victory Capital Management Inc | 0.03% | 660,110 | $53,726,353 | $63,766,626 | +$10,040,273 | +18.69% | |
| Two Sigma Investments, Lp | 0.03% | 568,709 | $46,287,226 | $54,937,289 | +$8,650,063 | +18.69% | |
| Aqr Capital Management Llc | 0.01% | 482,545 | $39,274,305 | $46,613,847 | +$7,339,542 | +18.69% | |
| Brown Advisory Inc | 0.05% | 408,468 | $33,245,234 | $39,458,009 | +$6,212,775 | +18.69% | |
| Jpmorgan Chase & Co | 0.00% | 370,574 | $29,998,212 | $35,797,448 | +$5,799,236 | +19.33% | |
| Charles Schwab Investment Management Inc | 0.00% | 355,658 | $28,947,005 | $34,356,563 | +$5,409,558 | +18.69% | |
| Gendell Jeffrey L | 0.24% | 324,504 | $26,411,381 | $31,347,086 | +$4,935,705 | +18.69% | |
| Royce & Associates Lp | 0.20% | 308,726 | $25,127,209 | $29,822,932 | +$4,695,723 | +18.69% | |
| Northern Trust Corp | 0.00% | 303,044 | $24,664,751 | $29,274,050 | +$4,609,299 | +18.69% | |
| Qube Research & Technologies Ltd | 0.03% | 285,849 | $23,265,250 | $27,613,013 | +$4,347,763 | +18.69% | |
| Acadian Asset Management Llc | 0.03% | 273,999 | $22,287,000 | $26,468,303 | +$4,181,303 | +18.76% | |
| Assenagon Asset Management S.A. | 0.03% | 272,782 | $22,201,727 | $26,350,741 | +$4,149,014 | +18.69% | |
| Western Standard Llc | 6.53% | 236,833 | $19,275,838 | $22,878,068 | +$3,602,230 | +18.69% | |
| Bank Of America Corp | 0.00% | 235,742 | $19,187,042 | $22,772,677 | +$3,585,635 | +18.69% | |
| Morgan Stanley | 0.00% | 230,793 | $18,784,284 | $22,294,604 | +$3,510,320 | +18.69% | |
| Renaissance Technologies LLC | Jim Simons | 0.02% | 185,000 | $15,057,150 | $17,871,000 | +$2,813,850 | +18.69% |
| Panagora Asset Management Inc | 0.05% | 182,538 | $14,856,768 | $17,633,171 | +$2,776,403 | +18.69% | |
| D. E. Shaw & Co., Inc. | 0.01% | 165,746 | $13,490,067 | $16,011,064 | +$2,520,997 | +18.69% | |
| Vanguard Fiduciary Trust Co | 0.00% | 163,715 | $13,324,764 | $15,814,869 | +$2,490,105 | +18.69% | |
| Sei Investments Co | 0.01% | 156,051 | $12,701,035 | $15,074,527 | +$2,373,492 | +18.69% | |
| Ubs Group Ag | 0.00% | 154,001 | $12,534,141 | $14,876,497 | +$2,342,356 | +18.69% | |
| First Wilshire Securities Management Inc | 2.47% | 147,112 | $11,973,446 | $14,211,019 | +$2,237,573 | +18.69% | |
| Mackenzie Financial Corp | 0.01% | 144,677 | $11,775,261 | $13,975,798 | +$2,200,537 | +18.69% | |
| Bank Of New York Mellon Corp | 0.00% | 137,261 | $11,171,701 | $13,259,413 | +$2,087,712 | +18.69% | |
| Hotchkis & Wiley Capital Management Llc | 0.03% | 135,740 | $11,047,879 | $13,112,484 | +$2,064,605 | +18.69% | |
| Leeward Investments, Llc - Ma | 0.46% | 125,308 | $10,198,818 | $12,104,753 | +$1,905,935 | +18.69% | |
| Janus Henderson Group Plc | 0.00% | 133,272 | $9,732,040 | $12,874,075 | +$3,142,035 | +32.29% | |
| Principal Financial Group Inc | 0.00% | 119,053 | $9,689,723 | $11,500,520 | +$1,810,797 | +18.69% | |
| Russell Investments Group, Ltd. | 0.01% | 118,614 | $9,642,448 | $11,458,112 | +$1,815,664 | +18.83% | |
| Invesco Ltd. | 0.00% | 118,427 | $9,638,773 | $11,440,048 | +$1,801,275 | +18.69% | |
| Zwj Investment Counsel Inc | 0.29% | 108,502 | $8,830,769 | $10,481,293 | +$1,650,524 | +18.69% | |
| Citadel Advisors Llc | 0.00% | 98,549 | $8,020,903 | $9,519,833 | +$1,498,930 | +18.69% | |
| Deprince Race & Zollo Inc | 0.13% | 93,348 | $7,597,594 | $9,017,417 | +$1,419,823 | +18.69% | |
| First Trust Advisors Lp | 0.00% | 91,252 | $7,426,999 | $8,814,943 | +$1,387,944 | +18.69% | |
| Teacher Retirement System Of Texas | 0.02% | 85,463 | $6,955,833 | $8,255,726 | +$1,299,893 | +18.69% | |
| Public Sector Pension Investment Board | 0.02% | 84,577 | $6,883,722 | $8,170,138 | +$1,286,416 | +18.69% | |
| Hrt Financial Lp | 0.01% | 84,349 | $6,865,000 | $8,148,113 | +$1,283,113 | +18.69% | |
| Mutual Of America Capital Management Llc | 0.07% | 82,920 | $6,748,859 | $8,010,072 | +$1,261,213 | +18.69% | |
| Fmr Llc | 0.00% | 82,759 | $6,735,794 | $7,994,519 | +$1,258,725 | +18.69% | |
| Proshare Advisors Llc | 0.01% | 81,232 | $6,611,472 | $7,847,011 | +$1,235,539 | +18.69% | |
| Sg Capital Management Llc | 0.52% | 71,022 | $5,780,481 | $6,860,725 | +$1,080,244 | +18.69% |
Frequently asked questions about IOSP
Who owns the most IOSP stock?
The largest holders of IOSP are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for INNOSPEC INC (IOSP).
Is IOSP widely held by superinvestors?
Many widely followed stocks like IOSP appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly IOSP is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.