Marathon Petroleum Corporation
US ˙ NYSE ˙ US56585A1025

SecurityMPC / Marathon Petroleum Corporation
InstitutionGAMMA Investing LLC
Latest Disclosed Ownership13,410 shares
Latest Disclosed Value $ 3,274,454
GAMMA Investing LLC reports 3.27% increase in ownership of MPC / Marathon Petroleum Corporation

On April 6, 2026 - GAMMA Investing LLC filed a 13F-HR form disclosing ownership of 13,410 shares of Marathon Petroleum Corporation (US:MPC) valued at $3,274,454 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 5, 2026 disclosing 12,986 shares of Marathon Petroleum Corporation. This represents a change in shares of 3.27% during the quarter. The current value of the position is $3,583,286 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-04-06 2026-03-31 13F MARATHON PETE CORP COM Common Stock 56585A102 13,410 424 3.27 3,274 55.09 0.1529
2026-01-05 2025-12-31 13F MARATHON PETE CORP COM Common Stock 56585A102 12,986 -263 -1.99 2,112 -17.31 0.1061
2025-10-02 2025-09-30 13F MARATHON PETE CORP COM Common Stock 56585A102 13,249 715 5.70 2,554 22.62 0.1408
2025-07-14 2025-06-30 13F MARATHON PETE CORP COM Common Stock 56585A102 12,534 1,957 18.50 2,082 35.19 0.1316
2025-04-15 2025-03-31 13F/A-1 MARATHON PETE CORP COM Common Stock 56585A102 10,577 351 3.43 1,541 7.99 0.1156
2025-04-07 2025-03-31 13F MARATHON PETE CORP COM Common Stock 56585A102 1,540,963 1,530,737 11 0.0564
2025-01-03 2024-12-31 13F MARATHON PETE CORP COM Common Stock 56585A102 10,226 -630 -5.80 1,427 -19.34 0.1216
2024-10-04 2024-09-30 13F MARATHON PETE CORP COM Common Stock 56585A102 10,856 558 1,769 0.1753
2024-10-07 2024-09-30 13F MARATHON PETE CORP COM Common Stock 56585A102 10,856 558 5.42 1,769 -1.01 0.1753
2024-07-02 2024-06-30 13F MARATHON PETE CORP COM Common Stock 56585A102 10,298 5,124 99.03 1,786 71.40 0.2434
2024-04-05 2024-03-31 13F MARATHON PETE CORP COM Common Stock 56585A102 5,174 393 8.22 1,043 31.73 0.2123
2024-02-01 2023-12-31 13F MARATHON PETE CORP COM Common Stock 56585A102 4,781 4,781 792 0.2144
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.