Mplx's top three insider shareholders as of June 06, 2026 are Michael J Hennigan (Executive Chairman, 359.14K shares), Frank M Semple (Vice Chairman, 333.34K shares), Maryann T. Mannen (Chairman, President Ceo, 165.46K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Pamela K.M. Beall | Exec Vp And Cfo | 43,247 | 0 | 13 Dec, 2021 |
| Christopher A Helms | - | 80,751 | 0 | 19 Feb, 2026 |
| John P Surma | - | 89,190 | 0 | 19 Feb, 2026 |
| Dan D Sandman | - | 127,542 | 0 | 05 Apr, 2023 |
| Frank M Semple | Vice Chairman | 0 | 333,337 | 03 Feb, 2022 |
| Gregory Scott Floerke | Exec. Vp And Coo | 95,337 | 0 | 03 Mar, 2026 |
| Michael J Hennigan | Executive Chairman | 359,137 | 0 | 16 Dec, 2025 |
| Maryann T. Mannen | Chairman, President Ceo | 165,459 | 0 | 03 Mar, 2026 |
| Ray N Jr Walker | - | 1,744 | 0 | 19 Feb, 2026 |
| J Michael Stice | - | 53,295 | 0 | 19 Feb, 2026 |
| Garry L. Peiffer | President | 64,072 | 0 | 19 Feb, 2026 |
| Donald C. Templin | President | 81,538 | 0 | 23 Nov, 2021 |
| John J Quaid | Exec Vp And Cfo | 52,393 | 0 | 04 Mar, 2025 |
| Carl Kristopher Hagedorn | Exec Vp Chief Fin Ofc | 20,409 | 0 | 03 Mar, 2026 |
| Thomas Kaczynski | Senior Vp, Finance Treasurer | 18,091 | 0 | 06 Dec, 2022 |
| Suzanne Gagle | General Counsel | 67,205 | 0 | 05 Dec, 2023 |
| Christine S Breves | - | 11,837 | 0 | 19 Feb, 2026 |
| Timothy J Aydt | Exec. Vp And Chief Comm Ofc. | 34,371 | 0 | 03 Mar, 2022 |
| Shawn M Lyon | Senior Vp, Log. Storage | 28,289 | 0 | 03 Mar, 2026 |
| Molly R Benson | Chief Legal Ofc Corp Sec | 46,114 | 0 | 03 Mar, 2026 |
| Maria A Khoury | - | 8,451 | 0 | 03 Mar, 2026 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 01 Mar, 2026 | Maryann T. Mannen | Common Units (Limited Partner Interests) | A | 52,817 | $0.00 | 178,679 | D | A |
| 01 Mar, 2026 | Gregory Scott Floerke | Common Units (Limited Partner Interests) | A | 5,986 | $0.00 | 98,229 | D | A |
| 01 Mar, 2026 | Shawn M Lyon | Common Units (Limited Partner Interests) | A | 5,986 | $0.00 | 31,040 | D | A |
| 01 Mar, 2026 | Carl Kristopher Hagedorn | Common Units (Limited Partner Interests) | A | 4,930 | $0.00 | 22,410 | D | A |
| 01 Mar, 2026 | Molly R Benson | Common Units (Limited Partner Interests) | A | 8,803 | $0.00 | 48,966 | D | A |
| 01 Mar, 2026 | Maria A Khoury | Common Units (Limited Partner Interests) | A | 8,451 | $0.00 | 8,451 | D | A |
| 02 Mar, 2026 | Maryann T. Mannen | Common Units (Limited Partner Interests) | D | 3,407 | $59.22 | 175,272 | D | F |
| 02 Mar, 2026 | Carl Kristopher Hagedorn | Common Units (Limited Partner Interests) | D | 422 | $59.22 | 21,988 | D | F |
| 02 Mar, 2026 | Molly R Benson | Common Units (Limited Partner Interests) | D | 614 | $59.22 | 48,352 | D | F |
| 02 Mar, 2026 | Shawn M Lyon | Common Units (Limited Partner Interests) | D | 920 | $59.22 | 30,120 | D | F |
| 02 Mar, 2026 | Gregory Scott Floerke | Common Units (Limited Partner Interests) | D | 995 | $59.22 | 97,234 | D | F |
| 02 Mar, 2026 | Molly R Benson | Common Units (Limited Partner Interests) | D | 1,240 | $59.22 | 47,112 | D | F |
| 02 Mar, 2026 | Gregory Scott Floerke | Common Units (Limited Partner Interests) | D | 1,100 | $59.22 | 96,134 | D | F |
| 02 Mar, 2026 | Shawn M Lyon | Common Units (Limited Partner Interests) | D | 1,033 | $59.22 | 29,087 | D | F |
| 02 Mar, 2026 | Maryann T. Mannen | Common Units (Limited Partner Interests) | D | 3,404 | $59.22 | 171,868 | D | F |
| 02 Mar, 2026 | Carl Kristopher Hagedorn | Common Units (Limited Partner Interests) | D | 916 | $59.22 | 21,072 | D | F |
| 02 Mar, 2026 | Gregory Scott Floerke | Common Units (Limited Partner Interests) | D | 797 | $59.22 | 95,337 | D | F |
| 02 Mar, 2026 | Carl Kristopher Hagedorn | Common Units (Limited Partner Interests) | D | 663 | $59.22 | 20,409 | D | F |
| 02 Mar, 2026 | Shawn M Lyon | Common Units (Limited Partner Interests) | D | 798 | $59.22 | 28,289 | D | F |
| 02 Mar, 2026 | Molly R Benson | Common Units (Limited Partner Interests) | D | 998 | $59.22 | 46,114 | D | F |