Ranked by reported Q2 2026 13F market value
Share of total reported institutional value in IOSP held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 4.4M | $356.6M | +13.0% | 17.788% | 0.01% |
| 2 | Allspring Global Investments Holdings, LLC | 1.9M | $154.7M | -18.3% | 7.683% | 0.24% |
| 3 | VANGUARD PORTFOLIO MANAGEMENT LLC | 1.9M | $153.4M | +1.3% | 7.650% | 0.01% |
| 4 | DIMENSIONAL FUND ADVISORS LP | 1.3M | $106.2M | +5.1% | 5.298% | 0.02% |
| 5 | VANGUARD CAPITAL MANAGEMENT LLC | 1.1M | $90.2M | -0.6% | 4.499% | 0.00% |
| 6 | STATE STREET CORP | 996K | $81.1M | +3.3% | 4.044% | 0.00% |
| 7 | Nuveen, LLC | 756K | $61.5M | +17.5% | 3.068% | 0.01% |
| 8 | GEODE CAPITAL MANAGEMENT, LLC | 667K | $54.3M | +5.7% | 2.706% | 0.00% |
| 9 | GOLDMAN SACHS GROUP INC | 662K | $53.9M | +34.6% | 2.688% | 0.00% |
| 10 | VICTORY CAPITAL MANAGEMENT INC | 660K | $53.7M | -23.7% | 2.680% | 0.03% |
| 11 | TWO SIGMA INVESTMENTS, LP | 569K | $46.3M | -4.1% | 2.309% | 0.03% |
| 12 | AQR CAPITAL MANAGEMENT LLC | 483K | $39.3M | +54.6% | 1.959% | 0.01% |
| 13 | BROWN ADVISORY INC | 408K | $33.2M | +37.8% | 1.658% | 0.05% |
| 14 | JPMORGAN CHASE & CO | 371K | $30.0M | -13.0% | 1.504% | 0.00% |
| 15 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 356K | $28.9M | -2.8% | 1.444% | 0.00% |
| 16 | GENDELL JEFFREY L | 325K | $26.4M | +10.2% | 1.317% | 0.23% |
| 17 | ROYCE & ASSOCIATES LP | 309K | $25.1M | +18.1% | 1.253% | 0.20% |
| 18 | NORTHERN TRUST CORP | 303K | $24.7M | +6.6% | 1.230% | 0.00% |
| 19 | Qube Research & Technologies Ltd | 286K | $23.3M | -29.7% | 1.161% | 0.02% |
| 20 | Assenagon Asset Management S.A. | 273K | $22.2M | -44.4% | 1.107% | 0.01% |
| 21 | Western Standard LLC | 237K | $19.3M | +4.4% | 0.962% | 6.53% |
| 22 | BANK OF AMERICA CORP /DE/ | 236K | $19.2M | -18.9% | 0.957% | 0.00% |
| 23 | MORGAN STANLEY | 231K | $18.8M | -2.0% | 0.937% | 0.00% |
| 24 | RENAISSANCE TECHNOLOGIES LLC | 185K | $15.1M | +55.6% | 0.751% | 0.02% |
| 25 | PANAGORA ASSET MANAGEMENT INC | 183K | $14.9M | +52.5% | 0.741% | 0.05% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in IOSP — a direct measure of their conviction.
Filings activity in IOSP during Q2 2026, grouped by how each filer changed its position.
Institutions that opened a new IOSP position in Q2 2026
Institutions that fully closed their IOSP position in Q2 2026
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q2 2026 | 280 | +6.1% | 99.84% | 1.39 pp | $1.96B | +9.5% |
| Q1 2026 | 264 | +2.7% | 101.23% | +2.06 pp | $1.79B | 2.8% |
| Q4 2025 | 257 | 1.2% | 99.17% | +1.42 pp | $1.84B | +0.4% |
| Q3 2025 | 260 | +1.2% | 97.75% | +0.40 pp | $1.83B | 8.1% |
| Q2 2025 | 257 | 4.1% | 97.35% | 1.75 pp | $1.99B | 12% |
| Q1 2025 | 268 | +5.1% | 99.10% | +1.04 pp | $2.26B | 13% |
| Q4 2024 | 255 | 0.8% | 98.06% | +0.83 pp | $2.60B | 1.7% |
| Q3 2024 | 257 | — | 97.23% | — | $2.64B | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying IOSP stock.
Based on Q2 2026 13F filings, institutional ownership of Innospec Inc. stands at 99.8%, held across 280 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of IOSP, with approximately 4,381,323 shares worth $0.36B as of Q2 2026.
Yes — 2 widely-followed marquee investors appear among the top 25 institutional holders of IOSP, including TWO SIGMA INVESTMENTS, LP, RENAISSANCE TECHNOLOGIES LLC.
Our composite Smart Money Score for IOSP is 48 out of 100 (Neutral). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
40 institutions opened new positions in IOSP during Q2 2026, while 27 fully exited. 172 added to existing positions and 61 trimmed.
IOSP institutional ownership fell by 1.39 percentage points quarter-over-quarter, with a net change of +16 holders.
The top 10 institutions account for 59.6% of all reported 13F value in IOSP, and the top 25 account for 79.3%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Innospec Inc. (IOSP) Institutional Ownership