Marathon Petroleum Corporation
US ˙ NYSE ˙ US56585A1025

SecurityMPC / Marathon Petroleum Corporation
InstitutionOppenheimer Asset Management Inc.
Latest Disclosed Ownership33,242 shares
Latest Disclosed Value $ 8,117,032
Oppenheimer Asset Management Inc. reports 0.80% decrease in ownership of MPC / Marathon Petroleum Corporation

On April 23, 2026 - Oppenheimer Asset Management Inc. filed a 13F-HR form disclosing ownership of 33,242 shares of Marathon Petroleum Corporation (US:MPC) valued at $8,117,032 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 33,511 shares of Marathon Petroleum Corporation. This represents a change in shares of -0.80% during the quarter. The current value of the position is $8,709,736 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)
2026-04-23 2026-03-31 13F MARATHON PETE COM 56585A102 33,242 -269 -0.80 8,117 48.96 0.0232
2026-02-02 2025-12-31 13F MARATHON PETE COM 56585A102 33,511 125 0.37 5,450 -15.31 0.0670
2025-11-06 2025-09-30 13F MARATHON PETE COM 56585A102 33,386 -9,920 -22.91 6,435 -10.55 0.0708
2025-07-31 2025-06-30 13F MARATHON PETE COM 56585A102 43,306 -1,081 -2.44 7,194 11.24 0.0825
2025-04-23 2025-03-31 13F MARATHON PETE COM 56585A102 44,387 3,291 8.01 6,467 12.81 0.0803
2025-02-05 2024-12-31 13F MARATHON PETE COM 56585A102 41,096 -2,078 -4.81 5,733 -18.50 0.0697
2024-11-05 2024-09-30 13F MARATHON PETE COM 56585A102 43,174 9,355 27.66 7,033 19.89 0.0847
2024-08-08 2024-06-30 13F MARATHON PETE COM 56585A102 33,819 -1,369 -3.89 5,867 -17.26 0.0749
2024-05-07 2024-03-31 13F MARATHON PETE COM 56585A102 35,188 -13,525 -27.76 7,090 -1.90 0.1039
2024-02-13 2023-12-31 13F MARATHON PETE COM 56585A102 48,713 -1,958 -3.86 7,227 -5.75 0.1005
2023-11-08 2023-09-30 13F MARATHON PETE COM 56585A102 50,671 655 1.31 7,669 31.50 0.1177
2023-08-03 2023-06-30 13F MARATHON PETE COM 56585A102 50,016 328 0.66 5,832 -12.96 0.0858
2023-05-10 2023-03-31 13F MARATHON PETE COM 56585A102 49,688 -17,250 -25.77 6,699 -14.01 0.1032
2023-02-07 2022-12-31 13F MARATHON PETE COM 56585A102 66,938 -9,269 -12.16 7,791 2.91 0.1254
2022-11-14 2022-09-30 13F MARATHON PETE COM 56585A102 76,207 881 1.17 7,570 22.23 0.1335
2022-08-08 2022-06-30 13F MARATHON PETE COM 56585A102 75,326 1,170 1.58 6,193 -2.32 0.1038
2022-05-12 2022-03-31 13F MARATHON PETE COM 56585A102 74,156 1,646 2.27 6,340 36.64 0.0900
2022-02-02 2021-12-31 13F MARATHON PETE COM 56585A102 72,510 1,949 2.76 4,640 6.40 0.0615
2021-11-12 2021-09-30 13F MARATHON PETE COM 56585A102 70,561 2,057 3.00 4,361 5.36 0.0620
2021-08-03 2021-06-30 13F MARATHON PETE COM 56585A102 68,504 2,908 4.43 4,139 17.95 0.0589
2021-05-17 2021-03-31 13F MARATHON PETE COM 56585A102 65,596 7,057 12.06 3,509 44.94 0.0544
2021-02-11 2020-12-31 13F MARATHON PETE COM 56585A102 58,539 1,957 3.46 2,421 45.84 0.0404
2020-11-13 2020-09-30 13F MARATHON PETE COM 56585A102 56,582 459 0.82 1,660 -20.88 0.0322
2020-08-11 2020-06-30 13F MARATHON PETE COM 56585A102 56,123 3,608 6.87 2,098 69.06 0.0433
2020-05-08 2020-03-31 13F MARATHON PETE COM 56585A102 52,515 -20,744 -28.32 1,241 -71.88 0.0305
2020-02-07 2019-12-31 13F MARATHON PETE COM 56585A102 73,259 5,785 8.57 4,413 7.66 0.0932
2019-10-31 2019-09-30 13F MARATHON PETE COM 56585A102 67,474 -282 -0.42 4,099 8.27 0.0911
2019-08-09 2019-06-30 13F MARATHON PETE COM 56585A102 67,756 17,457 34.71 3,786 25.78 0.0837
2019-04-24 2019-03-31 13F MARATHON PETE COM 56585A102 50,299 -310 -0.61 3,010 0.74 0.0676
2019-01-30 2018-12-31 13F MARATHON PETE COM 56585A102 50,609 1,345 2.73 2,988 -24.16 0.0740
2018-10-26 2018-09-30 13F MARATHON PETE COM 56585A102 49,264 19,889 67.71 3,940 91.17 0.0873
2018-08-10 2018-06-30 13F MARATHON PETE COM 56585A102 29,375 1,490 5.34 2,061 1.13 0.0504
2018-05-09 2018-03-31 13F MARATHON PETE COM 56585A102 27,885 -1,945 -6.52 2,038 21.82 0.0511
2018-02-07 2017-12-31 13F MARATHON PETE COM 56585A102 29,830 0 0.00 1,673 0.00 0.0444
2017-11-14 2017-09-30 13F MARATHON PETE COM 56585A102 29,830 -587 -1.93 1,673 5.09 0.0435
2017-08-09 2017-06-30 13F MARATHON PETE COM 56585A102 30,417 -114 -0.37 1,592 3.18 0.0440
2017-05-15 2017-03-31 13F MARATHON PETE COM 56585A102 30,531 30,531 1,543 0.0440
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.