Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionCalamos Wealth Management LLC
Latest Disclosed Ownership4,712 shares
Latest Disclosed Value $ 1,150,576
Calamos Wealth Management LLC reports 1.33% increase in ownership of MPC / Marathon Petroleum Corporation

On May 4, 2026 - Calamos Wealth Management LLC filed a 13F-HR form disclosing ownership of 4,712 shares of Marathon Petroleum Corporation (MX:MPC) valued at $1,150,576 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 29, 2026 disclosing 4,650 shares of Marathon Petroleum Corporation. This represents a change in shares of 1.33% 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)
2026-05-04 2026-03-31 13F MARATHON PETE COM 56585A102 4,712 62 1.33 1,151 52.12 0.0396
2026-01-29 2025-12-31 13F MARATHON PETE COM 56585A102 4,650 -1,202 -20.54 756 -32.92 0.0261
2025-10-20 2025-09-30 13F MARATHON PETE COM 56585A102 5,852 380 6.94 1,128 24.12 0.0406
2025-07-29 2025-06-30 13F MARATHON PETE COM 56585A102 5,472 814 17.48 909 33.92 0.0385
2025-04-29 2025-03-31 13F MARATHON PETE COM 56585A102 4,658 473 11.30 679 16.30 0.0338
2025-01-24 2024-12-31 13F MARATHON PETE COM 56585A102 4,185 89 2.17 584 -12.59 0.0292
2024-11-12 2024-09-30 13F MARATHON PETE COM 56585A102 4,096 907 28.44 667 20.61 0.0342
2024-07-25 2024-06-30 13F MARATHON PETE COM 56585A102 3,189 -76 -2.33 553 -15.83 0.0295
2024-05-08 2024-03-31 13F MARATHON PETE COM 56585A102 3,265 -231 -6.61 658 26.83 0.0369
2024-01-31 2023-12-31 13F MARATHON PETE COM 56585A102 3,496 -67 -1.88 519 -3.90 0.0326
2023-10-26 2023-09-30 13F MARATHON PETE COM 56585A102 3,563 -89 -2.44 539 26.82 0.0409
2023-07-28 2023-06-30 13F MARATHON PETE COM 56585A102 3,652 -137 -3.62 426 -16.67 0.0312
2023-05-04 2023-03-31 13F MARATHON PETE COM 56585A102 3,789 -9 -0.24 511 15.38 0.0400
2023-01-26 2022-12-31 13F MARATHON PETE COM 56585A102 3,798 0 0.00 442 17.24 0.0343
2022-10-24 2022-09-30 13F MARATHON PETE COM 56585A102 3,798 -367 -8.81 377 10.23 0.0323
2022-08-01 2022-06-30 13F MARATHON PETE COM 56585A102 4,165 -184 -4.23 342 -8.06 0.0303
2022-05-03 2022-03-31 13F MARATHON PETE COM 56585A102 4,349 108 2.55 372 37.27 0.0278
2022-02-01 2021-12-31 13F MARATHON PETE COM 56585A102 4,241 -686 -13.92 271 -11.15 0.0198
2021-10-26 2021-09-30 13F MARATHON PETE COM 56585A102 4,927 -75 -1.50 305 0.99 0.0246
2021-07-22 2021-06-30 13F MARATHON PETE COM 56585A102 5,002 -34 -0.68 302 12.27 0.0235
2021-04-12 2021-03-31 13F MARATHON PETE COM 56585A102 5,036 5,036 269 0.0222
2021-01-27 2020-12-31 13F MARATHON PETE COM 56585A102 0 -7,278 -100.00 0 -100.00
2020-10-26 2020-09-30 13F MARATHON PETE COM 56585A102 7,278 7,278 214 0.0245
2020-04-28 2020-03-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 0 -75,496 -100.00 0 -100.00
2020-01-15 2019-12-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 75,496 7,445 10.94 4,549 10.04 0.5359
2019-10-21 2019-09-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 68,051 1,882 2.84 4,134 11.79 0.5526
2019-08-07 2019-06-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 66,169 2,207 3.45 3,698 -3.40 0.4989
2019-04-12 2019-03-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 63,962 57,746 928.99 3,828 943.05 0.5468
2019-01-24 2018-12-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 6,216 6,216 367 0.0552
2018-04-13 2018-03-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 0 -40,737 -100.00 0 -100.00
2018-02-13 2017-12-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 40,737 -4,958 -10.85 2,688 4.88 0.3488
2017-10-25 2017-09-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 45,695 -580 -1.25 2,563 5.82 0.3552
2017-08-09 2017-06-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 46,275 166 0.36 2,422 3.95 0.3427
2017-04-20 2017-03-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 46,109 10,005 27.71 2,330 28.16 0.3483
2017-02-06 2016-12-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 36,104 1,991 5.84 1,818 31.26 0.2926
2016-11-14 2016-09-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 34,113 5,020 17.26 1,385 25.45 0.2367
2016-07-26 2016-06-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 29,093 4,220 16.97 1,104 19.35 0.1951
2016-04-25 2016-03-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 24,873 4,476 21.94 925 -12.49 0.1780
2016-02-05 2015-12-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 20,397 789 4.02 1,057 16.41 0.2105
2015-11-10 2015-09-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 19,608 1,167 6.33 908 -5.91 0.2179
2015-08-17 2015-06-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 18,441 15,408 508.01 965 210.29 0.2279
2015-05-12 2015-03-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 3,033 3,033 311 0.0777
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.