# Marathon Petroleum (MPC): value investors who own it

4 value investors held Marathon Petroleum in their Q3 2026 13F, led by Harris Associates (Oakmark), Matrix Asset Advisors, Horizon Kinetics, Mairs &…

## 13F holders

| Manager | Portfolio | Value | Change | Quarters held |
| --- | --- | --- | --- | --- |
| Harris Associates (Oakmark) | 0.1% | $58.6m | Trimmed -92% | 6 |
| Matrix Asset Advisors | 0.0% | $338k | Unchanged | 3 |
| Horizon Kinetics | 0.0% | $1.3m | Unchanged | 25 |
| Mairs & Power | 0.0% | $355k | Unchanged | 4 |

## Directors buying and selling (Form 4, last 12 months)

| Date | Who | Role | Bought or sold | Shares | Value |
| --- | --- | --- | --- | --- | --- |
| 2026-08-31 | Lyon Shawn M | SVP Log & Storage, MPLX GP LLC | Sold | 1000 | $376k |
| 2026-08-28 | Lyon Shawn M | SVP Log & Storage, MPLX GP LLC | Sold | 425 | $157k |
| 2026-08-27 | Brzezinski Erin M | VP and Controller | Sold | 570 | $207k |
| 2026-08-17 | Benson Molly R | Chief Legal Ofc & Corp Sec | Sold | 7196 | $2.6m |
| 2026-08-17 | Benson Molly R | Chief Legal Ofc & Corp Sec | Sold | 5000 | $1.8m |
| 2026-08-13 | Lyon Shawn M | SVP Log & Storage, MPLX GP LLC | Sold | 2500 | $875k |
| 2026-08-12 | Henschen Michael A II | Ex VP, Refining | Sold | 6011 | $2.1m |

Source: SEC filings, via moatshark (https://www.moatshark.com/s/mpc). Values traded and returns are estimates. Not investment advice. Built 2026-10-21.