As of March 23, 2026, the three largest insider holders of MPLX are Frank M Semple (Director, 333.34K shares), Maryann T. Mannen (Chairman, President Ceo, 165.46K shares), Dan D Sandman (Director, 127.54K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Frank M Semple | 0 | 333,337 | 03 Feb, 2022 | |
| Maryann T. Mannen | Chairman, President Ceo | 165,459 | 0 | 03 Mar, 2026 |
| Dan D Sandman | 127,542 | 0 | 05 Apr, 2023 | |
| John P Surma | 89,190 | 0 | 19 Feb, 2026 | |
| Donald C. Templin | 81,538 | 0 | 23 Nov, 2021 | |
| Suzanne Gagle | General Counsel | 67,205 | 0 | 05 Dec, 2023 |
| Garry L. Peiffer | 64,072 | 0 | 19 Feb, 2026 | |
| Frank M Semple | 58,172 | 0 | 19 Feb, 2026 | |
| J Michael Stice | 53,295 | 0 | 19 Feb, 2026 | |
| John J Quaid | 52,393 | 0 | 04 Mar, 2025 | |
| Molly R Benson | Chief Legal Ofc Corp Sec | 46,114 | 0 | 03 Mar, 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 |
| Shawn M Lyon | Senior Vp, Log. Storage | 28,289 | 0 | 03 Mar, 2026 |
| 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 |
| Christine S Breves | 11,837 | 0 | 19 Feb, 2026 | |
| Maria A Khoury | 8,451 | 0 | 03 Mar, 2026 | |
| Ray N Jr Walker | 1,744 | 0 | 19 Feb, 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 | Shawn M Lyon | Common Units (Limited Partner Interests) | A | 5,986 | $0.00 | 31,040 | D | A |
| 01 Mar, 2026 | Maryann T. Mannen | Common Units (Limited Partner Interests) | A | 52,817 | $0.00 | 178,679 | 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 | Carl Kristopher Hagedorn | Common Units (Limited Partner Interests) | D | 422 | $59.22 | 21,988 | D | F |
| 02 Mar, 2026 | Shawn M Lyon | Common Units (Limited Partner Interests) | D | 920 | $59.22 | 30,120 | D | F |
| 02 Mar, 2026 | Maryann T. Mannen | Common Units (Limited Partner Interests) | D | 3,407 | $59.22 | 175,272 | 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 | 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 | Shawn M Lyon | Common Units (Limited Partner Interests) | D | 1,033 | $59.22 | 29,087 | 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 | 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 | 6,409 | $59.22 | 165,459 | 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 |