MPLXP — Mplx LP Institutional Holders · Q2 2026
Who owns Mplx LP (MPLXP)? 3 institutions reported holding $72.40M in SEC 13F filings for Q2 2026 (period ended 2026-06-30). Largest holders: Group One Trading LLC ($40.6M), IMC-Chicago, LLC ($20.5M), Simplex Trading, LLC ($11.2M).
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | GROUP ONE TRADING LLC | $40.6M | 721,100 | Added |
| 2 | IMC-Chicago, LLC | $20.5M | 364,600 | Added |
| 3 | SIMPLEX TRADING, LLC | $11.2M | 199,600 | Trimmed |
Source: SEC Form 13F filings · as of 2026-06-30