Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionShelton Capital Management
Latest Disclosed Ownership5,217 shares
Latest Disclosed Value $ 1,273,887
Shelton Capital Management reports 16.76% increase in ownership of MPC / Marathon Petroleum Corporation

On May 15, 2026 - Shelton Capital Management filed a 13F-HR form disclosing ownership of 5,217 shares of Marathon Petroleum Corporation (MX:MPC) valued at $1,273,887 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 4,468 shares of Marathon Petroleum Corporation. This represents a change in shares of 16.76% 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)
2026-05-15 2026-03-31 13F MARATHON PETE COM 56585A102 5,217 749 16.76 1,274 75.34 0.0279
2026-02-17 2025-12-31 13F MARATHON PETE COM 56585A102 4,468 0 0.00 727 -15.68 0.0143
2025-11-14 2025-09-30 13F MARATHON PETE COM 56585A102 4,468 -913 -16.97 861 -3.58 0.0184
2025-08-13 2025-06-30 13F MARATHON PETE COM 56585A102 5,381 -6,660 -55.31 894 -49.09 0.0206
2025-05-15 2025-03-31 13F MARATHON PETE COM 56585A102 12,041 -110 -0.91 1,754 3.48 0.0418
2025-02-13 2024-12-31 13F MARATHON PETE COM 56585A102 12,151 0 0.00 1,695 -14.35 0.0422
2024-11-14 2024-09-30 13F MARATHON PETE COM 56585A102 12,151 -5,161 -29.81 1,980 -34.10 0.0508
2024-08-13 2024-06-30 13F MARATHON PETE COM 56585A102 17,312 -159 -0.91 3,003 -14.69 0.0815
2024-05-15 2024-03-31 13F MARATHON PETE COM 56585A102 17,471 -9,200 -34.49 3,520 -11.02 0.1000
2024-02-14 2023-12-31 13F MARATHON PETE COM 56585A102 26,671 9,961 59.61 3,957 56.49 0.1253
2023-11-14 2023-09-30 13F MARATHON PETE COM 56585A102 16,710 9,975 148.11 2,529 222.04 0.0926
2023-08-10 2023-06-30 13F MARATHON PETE COM 56585A102 6,735 -21 -0.31 785 -13.74 0.0282
2023-05-11 2023-03-31 13F MARATHON PETE COM 56585A102 6,756 3,846 132.16 911 169.23 0.0379
2023-02-13 2022-12-31 13F MARATHON PETE COM 56585A102 2,910 -4,330 -59.81 339 -52.99 0.0355
2022-11-14 2022-09-30 13F MARATHON PETE COM 56585A102 7,240 -263 -3.51 719 16.53 0.0342
2022-08-11 2022-06-30 13F MARATHON PETE COM 56585A102 7,503 -508 -6.34 617 -9.93 0.0278
2022-05-12 2022-03-31 13F MARATHON PETE COM 56585A102 8,011 -372 -4.44 685 27.80 0.0253
2022-02-11 2021-12-31 13F MARATHON PETE COM 56585A102 8,383 -199 -2.32 536 1.13 0.0190
2021-11-15 2021-09-30 13F MARATHON PETE COM 56585A102 8,582 -16,500 -65.78 530 -65.02 0.0207
2021-08-12 2021-06-30 13F MARATHON PETE COM 56585A102 25,082 0 0.00 1,515 12.89 0.0572
2021-05-14 2021-03-31 13F MARATHON PETE COM 56585A102 25,082 -500 -1.95 1,342 26.84 0.0467
2021-02-16 2020-12-31 13F MARATHON PETE COM 56585A102 25,582 3,108 13.83 1,058 60.55 0.0475
2020-11-09 2020-09-30 13F MARATHON PETE COM 56585A102 22,474 0 0.00 659 -21.55 0.0273
2020-08-12 2020-06-30 13F MARATHON PETE COM 56585A102 22,474 0 0.00 840 58.19 0.0463
2020-05-13 2020-03-31 13F MARATHON PETE COM 56585A102 22,474 0 0.00 531 -60.78 0.0385
2020-02-11 2019-12-31 13F MARATHON PETE COM 56585A102 22,474 -1,921 -7.87 1,354 -8.64 0.0748
2019-11-13 2019-09-30 13F MARATHON PETE COM 56585A102 24,395 0 0.00 1,482 8.73 0.0875
2019-08-14 2019-06-30 13F MARATHON PETE COM 56585A102 24,395 22,937 1,573.18 1,363 -94.40 0.0785
2019-05-10 2019-03-31 13F MARATHON PETE COM 56585A102 1,458 -22,924 -94.02 24,357 1,592.63 0.0961
2019-01-31 2018-12-31 13F MARATHON PETE COM 56585A102 24,382 2,484 11.34 1,439 -17.82 0.0979
2018-11-14 2018-09-30 13F MARATHON PETE COM 56585A102 21,898 0 0.00 1,751 14.00 0.0999
2018-08-10 2018-06-30 13F MARATHON PETE COM 56585A102 21,898 0 0.00 1,536 -4.06 0.0955
2018-05-15 2018-03-31 13F MARATHON PETE COM 56585A102 21,898 -500 -2.23 1,601 8.32 0.1050
2018-02-06 2017-12-31 13F MARATHON PETE COM 56585A102 22,398 0 0.00 1,478 17.68 0.0949
2017-11-28 2017-09-30 13F/A-1 MARATHON PETE COM 56585A102 22,398 -100 -0.44 1,256 6.71 0.0848
2017-11-14 2017-09-30 13F MARATHON PETE COM 56585A102 22,398 -100 1,256
2017-08-14 2017-06-30 13F MARATHON PETE COM 56585A102 22,498 15,700 230.95 1,177 242.15 0.0832
2017-11-28 2017-03-31 13F/A-1 MARATHON PETE COM 56585A102 6,798 900 15.26 344 15.82 0.0238
2017-11-28 2016-12-31 13F/A-2 MARATHON PETE COM 56585A102 5,898 -4,900 -45.38 297 -32.19 0.0226
2017-12-06 2016-09-30 13F/A-2 MARATHON PETE COM 56585A102 10,798 -11,500 -51.57 438 -48.23 0.0366
2017-12-04 2016-09-30 13F/A-1 MARATHON PETE COM 56585A102 5,898 -4,900 297 0.0189
2016-11-14 2016-09-30 13F MARATHON PETE COM 56585A102 10,798 -11,500 438
2016-08-01 2016-06-30 13F MARATHON PETE COM 56585A102 22,298 -2,700 -10.80 846 -8.93 0.0745
2016-05-13 2016-03-31 13F MARATHON PETE COM 56585A102 24,998 4,000 19.05 929 -14.69 0.0841
2016-02-01 2015-12-31 13F MARATHON PETE COM 56585A102 20,998 13,300 172.77 1,089 205.04 0.1053
2015-11-02 2015-09-30 13F MARATHON PETE COM 56585A102 7,698 3,000 63.86 357 45.12 0.0393
2015-08-11 2015-06-30 13F MARATHON PETE COM 56585A102 4,698 2,009 74.71 246 -10.55 0.0254
2015-05-12 2015-03-31 13F MARATHON PETE COM 56585A102 2,689 200 8.04 275 22.22 0.0297
2015-02-10 2014-12-31 13F MARATHON PETE COM 56585A102 2,489 0 0.00 225 6.64 0.0262
2014-10-15 2014-09-30 13F MARATHON PETE COM 56585A102 2,489 0 0.00 211 -2.76 0.0284
2014-04-14 2014-03-31 13F MARATHON PETE COM 56585A102 2,489 0 0.00 217 -4.82 0.0318
2014-01-22 2013-12-31 13F MARATHON PETE COM 56585A102 2,489 2,489 228 0.0345
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.