According to recent filings covering the 90 days ending January 10, 2026, the three most significant insider holders at Mplx Lp are Director Frank M Semple (390.44K shares), Executive Chairman Michael J Hennigan (359.14K shares), Director Dan D Sandman (127.54K shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Frank M Semple | 390,438 | 18 Nov, 2025 | |
| Michael J Hennigan | Executive Chairman | 359,137 | 16 Dec, 2025 |
| Dan D Sandman | 127,542 | 05 Apr, 2023 | |
| Maryann T. Mannen | President & Ceo | 125,862 | 04 Mar, 2025 |
| Gregory Scott Floerke | Exec. Vp And Coo | 92,243 | 16 Dec, 2025 |
| John P Surma | 87,685 | 18 Nov, 2025 | |
| Donald C. Templin | 81,538 | 23 Nov, 2021 | |
| Christopher A Helms | 79,466 | 18 Nov, 2025 | |
| Suzanne Gagle | General Counsel | 67,205 | 05 Dec, 2023 |
| Garry L. Peiffer | 62,892 | 18 Nov, 2025 | |
| John J Quaid | 52,393 | 04 Mar, 2025 | |
| J Michael Stice | 52,313 | 18 Nov, 2025 | |
| Michael L Beatty | 51,726 | 05 Apr, 2021 | |
| Pamela K.M. Beall | 43,247 | 13 Dec, 2021 | |
| Molly R Benson | Chief Legal Ofc & Corp Sec | 40,163 | 16 Dec, 2025 |
| Timothy J Aydt | Exec. Vp And Chief Comm Ofc. | 34,371 | 03 Mar, 2022 |
| Shawn M Lyon | Senior Vp And Log. & Storage | 25,054 | 16 Dec, 2025 |
| Thomas Kaczynski | Senior Vp And Finance & Treasurer | 18,091 | 06 Dec, 2022 |
| Carl Kristopher Hagedorn | Exec Vp & Chief Fin Ofc | 17,480 | 04 Mar, 2025 |
| Christine S Breves | 11,619 | 18 Nov, 2025 | |
| Ray N Jr Walker | 1,712 | 18 Nov, 2025 |
* 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 |
|---|---|---|---|---|---|---|---|---|
| 12 Dec, 2025 | Gregory Scott Floerke | Common Units (Limited Partner Interests) | D | 242 | $54.85 | 92,243 | D | F |
| 12 Dec, 2025 | Michael J Hennigan | Common Units (Limited Partner Interests) | D | 1,335 | $54.85 | 359,137 | D | F |
| 12 Dec, 2025 | Shawn M Lyon | Common Units (Limited Partner Interests) | D | 245 | $54.85 | 25,054 | D | F |
| 12 Dec, 2025 | Molly R Benson | Common Units (Limited Partner Interests) | D | 306 | $54.85 | 40,163 | D | F |
| 14 Nov, 2025 | Christopher A Helms | Common Units (Limited Partner Interests) | A | 1,358 | $0.00 | 79,466 | D | A |
| 14 Nov, 2025 | John P Surma | Common Units (Limited Partner Interests) | A | 1,590 | $0.00 | 87,685 | D | A |
| 14 Nov, 2025 | Frank M Semple | Common Units (Limited Partner Interests) | A | 1,132 | $0.00 | 57,101 | D | A |
| 14 Nov, 2025 | Ray N Jr Walker | Common Units (Limited Partner Interests) | A | 34 | $0.00 | 1,712 | D | A |
| 14 Nov, 2025 | J Michael Stice | Common Units (Limited Partner Interests) | A | 1,037 | $0.00 | 52,313 | D | A |
| 14 Nov, 2025 | Garry L. Peiffer | Common Units (Limited Partner Interests) | A | 1,247 | $0.00 | 62,892 | D | A |
| 14 Nov, 2025 | Christine S Breves | Common Units (Limited Partner Interests) | A | 230 | $0.00 | 11,619 | D | A |
| 25 Aug, 2025 | Ray N Jr Walker | Common Units (Limited Partner Interests) | A | 1,678 | $0.00 | 1,678 | D | A |
| 15 Aug, 2025 | Christopher A Helms | Common Units (Limited Partner Interests) | A | 1,260 | $0.00 | 78,108 | D | A |
| 15 Aug, 2025 | John P Surma | Common Units (Limited Partner Interests) | A | 1,475 | $0.00 | 86,095 | D | A |
| 15 Aug, 2025 | Frank M Semple | Common Units (Limited Partner Interests) | A | 1,051 | $0.00 | 55,968 | D | A |
| 15 Aug, 2025 | J Michael Stice | Common Units (Limited Partner Interests) | A | 962 | $0.00 | 51,276 | D | A |
| 15 Aug, 2025 | Garry L. Peiffer | Common Units (Limited Partner Interests) | A | 1,157 | $0.00 | 61,645 | D | A |
| 15 Aug, 2025 | Christine S Breves | Common Units (Limited Partner Interests) | A | 214 | $0.00 | 11,389 | D | A |
| 16 May, 2025 | Christopher A Helms | Common Units (Limited Partner Interests) | A | 1,187 | $0.00 | 76,849 | D | A |
| 16 May, 2025 | John P Surma | Common Units (Limited Partner Interests) | A | 1,390 | $0.00 | 84,620 | D | A |