Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionGreat Valley Advisor Group, Inc.
Latest Disclosed Ownership2,059 shares
Latest Disclosed Value $ 503,046
Great Valley Advisor Group, Inc. reports 5.16% increase in ownership of MPC / Marathon Petroleum Corporation

On May 11, 2026 - Great Valley Advisor Group, Inc. filed a 13F-HR form disclosing ownership of 2,059 shares of Marathon Petroleum Corporation (MX:MPC) valued at $503,046 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 1,958 shares of Marathon Petroleum Corporation. This represents a change in shares of 5.16% during the quarter.

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)
2026-05-11 2026-03-31 13F MARATHON PETE COM 56585A102 2,059 101 5.16 503 58.18 0.0091
2026-02-12 2025-12-31 13F MARATHON PETE COM 56585A102 1,958 -16 -0.81 319 -16.32 0.0061
2025-11-14 2025-09-30 13F MARATHON PETE COM 56585A102 1,974 -202 -9.28 380 5.26 0.0076
2025-08-14 2025-06-30 13F MARATHON PETE COM 56585A102 2,176 149 7.35 362 22.37 0.0080
2025-05-08 2025-03-31 13F MARATHON PETE COM 56585A102 2,027 272 15.50 295 20.41 0.0064
2025-02-24 2024-12-31 13F MARATHON PETE COM 56585A102 1,755 1 0.06 245 -14.04 0.0055
2024-11-12 2024-09-30 13F MARATHON PETE COM 56585A102 1,754 -441 -20.09 285 -25.00 0.0070
2024-07-16 2024-06-30 13F MARATHON PETE COM 56585A102 2,195 -208 -8.66 380 -21.33 0.0106
2024-05-06 2024-03-31 13F MARATHON PETE COM 56585A102 2,403 478 24.83 484 68.88 0.0147
2024-02-06 2023-12-31 13F MARATHON PETE COM 56585A102 1,925 -502 -20.68 286 -22.07 0.0100
2023-11-07 2023-09-30 13F MARATHON PETE COM 56585A102 2,427 -95 -3.77 367 24.83 0.0152
2023-08-10 2023-06-30 13F MARATHON PETE COM 56585A102 2,522 -307 -10.85 294 -22.83 0.0123
2023-05-03 2023-03-31 13F MARATHON PETE COM 56585A102 2,829 -9,943 -77.85 381 -74.36 0.0178
2023-02-01 2022-12-31 13F MARATHON PETE COM 56585A102 12,772 -4,649 -26.69 1,487 -14.15 0.0760
2022-10-21 2022-09-30 13F MARATHON PETE COM 56585A102 17,421 -18 -0.10 1,731 20.71 0.0969
2022-07-19 2022-06-30 13F MARATHON PETE COM 56585A102 17,439 3,811 27.96 1,434 23.41 0.0788
2022-04-20 2022-03-31 13F MARATHON PETE COM 56585A102 13,628 9,601 238.42 1,162 352.14 0.0678
2022-02-10 2021-12-31 13F MARATHON PETE COM 56585A102 4,027 -329 -7.55 257 -4.46 0.0159
2021-10-14 2021-09-30 13F MARATHON PETE COM 56585A102 4,356 -3,490 -44.48 269 -43.13 0.0185
2021-07-27 2021-06-30 13F MARATHON PETE COM 56585A102 7,846 3,297 72.48 473 94.65 0.0350
2021-04-20 2021-03-31 13F MARATHON PETE COM 56585A102 4,549 -979 -17.71 243 6.58 0.0234
2021-01-29 2020-12-31 13F MARATHON PETE COM 56585A102 5,528 5,528 228 0.0236
2020-10-21 2020-09-30 13F MARATHON PETE COM 56585A102 0 -11,908 -100.00 0 -100.00
2020-07-31 2020-06-30 13F MARATHON PETE COM 56585A102 11,908 -1,286 -9.75 445 42.63 0.0728
2020-05-15 2020-03-31 13F MARATHON PETE COM 56585A102 13,194 6,860 108.30 312 -18.32 0.0826
2020-02-10 2019-12-31 13F MARATHON PETE COM 56585A102 6,334 417 7.05 382 6.41 0.0851
2019-10-25 2019-09-30 13F MARATHON PETE COM 56585A102 5,917 -16,326 -73.40 359 -71.14 0.0867
2019-07-30 2019-06-30 13F MARATHON PETE COM 56585A102 22,243 17,517 370.65 1,244 339.58 0.3126
2019-04-26 2019-03-31 13F MARATHON PETE COM 56585A102 4,726 384 8.84 283 10.55 0.0901
2019-04-11 2018-12-31 13F MARATHON PETE COM 56585A102 4,342 4,342 256 0.0956
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.