Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionWestwood Holdings Group Inc
Latest Disclosed Ownership8,672 shares
Latest Disclosed Value $ 2,117,529
Westwood Holdings Group Inc reports 50.09% increase in ownership of MPC / Marathon Petroleum Corporation

On May 15, 2026 - Westwood Holdings Group Inc filed a 13F-HR form disclosing ownership of 8,672 shares of Marathon Petroleum Corporation (MX:MPC) valued at $2,117,529 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 5,778 shares of Marathon Petroleum Corporation. This represents a change in shares of 50.09% 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.

Upgrade to unlock premium data and export to Excel .

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 8,672 2,894 50.09 2,118 125.45 0.0154
2026-02-17 2025-12-31 13F MARATHON PETE COM 56585A102 5,778 -871 -13.10 940 -26.76 0.0076
2025-11-14 2025-09-30 13F MARATHON PETE COM 56585A102 6,649 2,420 57.22 1,282 82.62 0.0091
2025-10-08 2025-06-30 13F/A-2 MARATHON PETE COM 56585A102 4,229 225 5.62 702 20.41 0.0051
2025-08-18 2025-06-30 13F/A-1 MARATHON PETE COM 56585A102 4,229 225 702 0.0052
2025-08-08 2025-06-30 13F MARATHON PETE COM 56585A102 4,229 225 702 0.0062
2025-05-09 2025-03-31 13F MARATHON PETE COM 56585A102 4,004 470 13.30 583 18.50 0.0044
2025-02-14 2024-12-31 13F MARATHON PETE COM 56585A102 3,534 -353 -9.08 493 -22.27 0.0038
2024-11-14 2024-09-30 13F MARATHON PETE COM 56585A102 3,887 367 10.43 633 3.77 0.0027
2024-08-13 2024-06-30 13F MARATHON PETE COM 56585A102 3,520 3,520 611 0.0029
2023-05-12 2023-03-31 13F MARATHON PETE COM 56585A102 0 -1,943 -100.00 0 -100.00
2023-02-14 2022-12-31 13F MARATHON PETE COM 56585A102 1,943 1,943 226 0.0020
2020-08-13 2020-06-30 13F MARATHON PETE COM 56585A102 0 -34,975 -100.00 0 -100.00
2020-05-15 2020-03-31 13F MARATHON PETE COM 56585A102 34,975 150 0.43 826 -60.63 0.0125
2020-02-14 2019-12-31 13F MARATHON PETROLEUM COM 56585A102 34,825 0 0.00 2,098 -0.85 0.0224
2019-11-14 2019-09-30 13F MARATHON PETROLEUM COM 56585A102 34,825 -8,381 -19.40 2,116 -12.34 0.0234
2019-08-14 2019-06-30 13F MARATHON PETROLEUM COM 56585A102 43,206 1,820 4.40 2,414 -2.54 0.0263
2019-05-13 2019-03-31 13F MARATHON PETE COM 56585A102 41,386 -2,530 -5.76 2,477 -4.40 0.0257
2019-02-14 2018-12-31 13F Marathon Pete COM 56585A102 43,916 1,716 4.07 2,591 -23.23 0.0296
2018-11-14 2018-09-30 13F Marathon Pete COM 56585A102 42,200 0 0.00 3,375 13.98 0.0296
2018-08-13 2018-06-30 13F Marathon Pete COM 56585A102 42,200 0 0.00 2,961 -4.02 0.0249
2018-05-14 2018-03-31 13F Marathon Pete COM 56585A102 42,200 -2,280 -5.13 3,085 5.11 0.0250
2018-02-15 2017-12-31 13F/A-1 Marathon Pete COM 56585A102 44,480 -13,150 -22.82 2,935 -9.19 0.0221
2018-02-14 2017-12-31 13F Marathon Pete COM 56585A102 44,480 2,935
2017-11-14 2017-09-30 13F Marathon Pete COM 56585A102 57,630 -25,125 -30.36 3,232 -25.38 0.0257
2017-08-15 2017-06-30 13F Marathon Pete COM 56585A102 82,755 24,400 41.81 4,331 46.86 0.0353
2017-05-15 2017-03-31 13F Marathon Pete COM 56585A102 58,355 -6,295 -9.74 2,949 -9.40 0.0240
2017-02-17 2016-12-31 13F/A-1 Marathon Pete COM 56585A102 64,650 -18,050 -21.83 3,255 -3.04 0.0266
2016-11-14 2016-09-30 13F Marathon Pete COM 56585A102 82,700 17,100 26.07 3,357 34.82 0.0285
2016-08-15 2016-06-30 13F Marathon Pete COM 56585A102 65,600 0 0.00 2,490 2.09 0.0221
2016-05-16 2016-03-31 13F Marathon Pete COM 56585A102 65,600 -731,960 -91.77 2,439 -94.10 0.0211
2016-02-16 2015-12-31 13F Marathon Pete COM 56585A102 797,560 -14,177 -1.75 41,346 9.94 0.3589
2015-11-16 2015-09-30 13F MARATHON PETE COM 56585A102 811,737 742,237 1,067.97 37,607 934.30 0.3257
2015-08-17 2015-06-30 13F MARATHON PETE COM 56585A102 69,500 34,750 100.00 3,636 2.19 0.0273
2015-05-08 2015-03-31 13F MARATHON PETE COM 56585A102 34,750 0 0.00 3,558 13.42 0.0271
2015-02-17 2014-12-31 13F MARATHON PETE COM 56585A102 34,750 0 0.00 3,137 6.63 0.0242
2014-11-13 2014-09-30 13F MARATHON PETE COM 56585A102 34,750 0 0.00 2,942 8.44 0.0232
2014-08-14 2014-06-30 13F MARATHON PETE COM 56585A102 34,750 0 0.00 2,713 -10.31 0.0200
2014-05-14 2014-03-31 13F MARATHON PETE COM 56585A102 34,750 0 0.00 3,025 -5.11 0.0233
2014-02-11 2013-12-31 13F MARATHON PETE COM 56585A102 34,750 0 0.00 3,188 42.64 0.0245
2013-11-08 2013-09-30 13F MARATHON PETE CORP COM COM 56585A102 34,750 20,000 135.59 2,235 113.26 0.0189
2013-08-13 2013-06-30 13F MARATHON PETE CORP COM COM 56585A102 14,750 14,750 1,048 0.0092
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.