7 institutions reported holding $92.0M of ARCELORMITTAL SA LUXEMBOURG (MT.WS) in SEC 13F filings for 2026-03-31. Largest institutional holders: Optiver Holding B.V. ($68.9M), GROUP ONE TRADING LLC ($9.7M), SIMPLEX TRADING, LLC ($7.5M), IMC-Chicago, LLC ($5.9M), SG Americas Securities, LLC ($0). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | Optiver Holding B.V. | $68.9M | 1.3M | Trimmed |
| 2 | GROUP ONE TRADING LLC | $9.7M | 187,200 | Added |
| 3 | SIMPLEX TRADING, LLC | $7.5M | 143,500 | Trimmed |
| 4 | IMC-Chicago, LLC | $5.9M | 113,400 | Added |
| 5 | SG Americas Securities, LLC | $0 | 0 | Exited |
| 6 | L & S Advisors Inc | $0 | 0 | Exited |
| 7 | CenterStar Asset Management, LLC | $0 | 0 | Exited |
Source: SEC Form 13F filings · as of 2026-03-31