Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionMengis Capital Management, Inc.
Latest Disclosed Ownership10,300 shares
Latest Disclosed Value $ 2,515,054
Mengis Capital Management, Inc. ownership in MPC / Marathon Petroleum Corporation

On May 12, 2026 - Mengis Capital Management, Inc. filed a 13F-HR form disclosing ownership of 10,300 shares of Marathon Petroleum Corporation (MX:MPC) valued at $2,515,054 USD as of March 31, 2026. The entity filed a previous 13F-HR on March 5, 2026 disclosing 10,300 shares of Marathon Petroleum Corporation. This represents a change in shares of 0.00% 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)
2026-05-12 2026-03-31 13F MARATHON PETR CRP COM 56585A102 10,300 0 0.00 2,515 50.15 0.4329
2026-03-05 2025-12-31 13F MARATHON PETR CRP COM 56585A102 10,300 -275 -2.60 1,675 -17.81 0.2961
2025-11-12 2025-09-30 13F MARATHON PETR CRP COM 56585A102 10,575 0 0.00 2,038 16.06 0.4008
2025-07-24 2025-06-30 13F MARATHON PETR CRP COM 56585A102 10,575 -100 -0.94 1,757 12.93 0.3732
2025-05-08 2025-03-31 13F MARATHON PETR CRP COM 56585A102 10,675 0 0.00 1,555 4.43 0.3247
2025-02-04 2024-12-31 13F MARATHON PETR CRP COM 56585A102 10,675 -300 -2.73 1,489 -16.68 0.3042
2024-11-05 2024-09-30 13F MARATHON PETR CRP COM 56585A102 10,975 0 0.00 1,788 -6.10 0.3518
2024-08-13 2024-06-30 13F/A-1 MARATHON PETE COM 56585A102 10,975 -850 -7.19 1,904 -20.11 0.3859
2024-07-17 2024-06-30 13F MARATHON PETE COM 56585A102 11,825 0 2,383 0.3397
2024-05-14 2024-03-31 13F/A-1 MARATHON PETE COM 56585A102 11,825 150 1.28 2,383 37.53 0.3674
2024-05-07 2024-03-31 13F MARATHON PETE COM 56585A102 11,675 0 1,732 0.3246
2024-02-01 2023-12-31 13F MARATHON PETE COM 56585A102 11,675 -2,200 -15.86 1,732 -17.48 0.3246
2023-11-09 2023-09-30 13F MARATHON PETE COM 56585A102 13,875 0 0.00 2,100 29.81 0.4364
2023-08-08 2023-06-30 13F MARATHON PETE COM 56585A102 13,875 -375 -2.63 1,618 -15.83 0.3228
2023-05-05 2023-03-31 13F MARATHON PETE COM 56585A102 14,250 -3,075 -17.75 1,921 95,950.00 0.4048
2023-02-01 2022-12-31 13F MARATHON PETE CORP COM COM 56585A102 17,325 -100 -0.57 2 -99.88 0.4395
2022-11-04 2022-09-30 13F MARATHON PETE CORP COM COM 56585A102 17,425 -1,350 -7.19 1,730 12.12 0.4098
2022-07-19 2022-06-30 13F MARATHON PETE CORP COM COM 56585A102 18,775 -6,810 -26.62 1,543 -29.45 0.3389
2022-05-02 2022-03-31 13F MARATHON PETE CORP COM COM 56585A102 25,585 -600 -2.29 2,187 30.57 0.4192
2022-02-04 2021-12-31 13F MARATHON PETE CORP COM COM 56585A102 26,185 -300 -1.13 1,675 2.32 0.3145
2021-11-03 2021-09-30 13F MARATHON PETE CORP COM COM 56585A102 26,485 0 0.00 1,637 2.31 0.3438
2021-08-16 2021-06-30 13F/A-1 MARATHON PETE CORP COM COM 56585A102 26,485 -465 -1.73 1,600 11.03 0.3316
2021-07-21 2021-06-30 13F MARATHON PETE CORP COM COM 56585A102 26,950 0 1,441 0.3187
2021-05-07 2021-03-31 13F MARATHON PETE CORP COM COM 56585A102 26,950 -50 -0.19 1,441 29.12 0.3192
2021-02-03 2020-12-31 13F MARATHON PETE CORP COM COM 56585A102 27,000 50 0.19 1,116 41.27 0.2711
2020-10-29 2020-09-30 13F MARATHON PETE CORP COM COM 56585A102 26,950 -415 -1.52 790 -22.70 0.2167
2020-07-22 2020-06-30 13F MARATHON PETE CORP COM COM 56585A102 27,365 -10,935 -28.55 1,022 13.05 0.3035
2020-05-06 2020-03-31 13F MARATHON PETE CORP COM COM 56585A102 38,300 1,725 4.72 904 -58.97 0.3088
2020-02-06 2019-12-31 13F MARATHON PETE CORP COM COM 56585A102 36,575 8,225 29.01 2,203 27.93 0.6068
2019-11-05 2019-09-30 13F MARATHON PETE CORP COM COM 56585A102 28,350 14,475 104.32 1,722 122.19 0.5131
2019-07-18 2019-06-30 13F MARATHON PETE CORP COM COM 56585A102 13,875 2,950 27.00 775 18.68 0.2371
2019-05-06 2019-03-31 13F MARATHON PETE CORP COM COM 56585A102 10,925 10,925 653 0.3644
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.