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IOSP · Innospec Inc.

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Market Cap
$2.28B
Shares
24.63M

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 282
Total Value: $2,001,778,263
Total Shares: 24,595,409
Showing 1–100 of 282 holdings by value · page 1 of 3

Institutional Ownership Trend

26 quarters

Holder Concentration

Across 282 13F filers · Δ vs Mar 31, 2026
Top Holder
17.8%
Sep 2023 → Jun 2026 · range 15.0% – 17.8%
+2.3 pts
Top 5
43.0%
Sep 2023 → Jun 2026 · range 41.7% – 52.1%
+1.2 pts
Top 10
58.2%
Sep 2023 → Jun 2026 · range 56.6% – 69.9%
+1.6 pts
HHI
567
Sep 2023 → Jun 2026 · range 513 – 703
Broadly held+54

Quarterly Activity

vs Mar 31, 2026
New
46
Increased
103
Decreased
97
Sold Out
30
Unchanged
36
Holder count: +16
Institutional value: +9.9%
Shares held: -1.4%

Top Buyers

vs Mar 31, 2026
Institution Added Now Holds Open

Top Sellers

vs Mar 31, 2026
Institution Sold Now Holds Open

Top New Positions

vs Mar 31, 2026
Institution Acquired Value (USD) Open

Top Sold-Out Positions

vs Mar 31, 2026
Institution Previously Held Last Value (USD) Open
Showing 100 of 282
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Holder Value (USD) % of 13F Shares Open
Key facts CIK 1054905 CUSIP 45768S105 13F (30d) 219 filings 219 filers Visit website