Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionBoston Private Wealth Llc
Latest Disclosed Ownership5,317 shares
Latest Disclosed Value $ 1,298,061
Boston Private Wealth Llc reports 4.58% decrease in ownership of MPC / Marathon Petroleum Corporation

On April 17, 2026 - Boston Private Wealth Llc filed a 13F-HR form disclosing ownership of 5,317 shares of Marathon Petroleum Corporation (MX:MPC) valued at $1,298,061 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 4, 2026 disclosing 5,572 shares of Marathon Petroleum Corporation. This represents a change in shares of -4.58% 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)
2026-04-17 2026-03-31 13F MARATHON PETROLEUM CORP COM US COM 56585A102 5,317 -255 -4.58 1,298 43.27 0.0855
2026-02-04 2025-12-31 13F MARATHON PETROLEUM CORP COM US COM 56585A102 5,572 -241 -4.15 906 -19.11 0.0534
2025-11-06 2025-09-30 13F MARATHON PETROLEUM CORP COM US COM 56585A102 5,813 -550 -8.64 1,120 5.96 0.0603
2025-08-14 2025-06-30 13F MARATHON PETROLEUM CORP COM US COM 56585A102 6,363 -3,611 -36.20 1,057 -27.25 0.0566
2025-05-14 2025-03-31 13F MARATHON PETROLEUM CORP COM US COM 56585A102 9,974 897 9.88 1,453 14.77 0.0597
2025-02-05 2024-12-31 13F MARATHON PETROLEUM CORP COM US COM 56585A102 9,077 9,077 1,266 0.0237
2024-10-18 2024-09-30 13F MARATHON PETROLEUM CORP COM US COM 56585A102 0 -9,264 -100.00 0 -100.00
2024-08-06 2024-06-30 13F MARATHON PETROLEUM CORP COM US COM 56585A102 9,264 -1,498 -13.92 1,607 -25.88 0.0398
2024-05-15 2024-03-31 13F MARATHON PETROLEUM CORP COM US COM 56585A102 10,762 -498 -4.42 2,169 29.82 0.0483
2024-01-30 2023-12-31 13F MARATHON PETROLEUM CORP COM US COM 56585A102 11,260 910 8.79 1,671 6.64 0.0406
2023-10-23 2023-09-30 13F MARATHON PETROLEUM CORP COM US COM 56585A102 10,350 -1,862 -15.25 1,566 10.05 0.0344
2023-07-24 2023-06-30 13F MARATHON PETROLEUM CORP COM US COM 56585A102 12,212 -648 -5.04 1,424 -17.89 0.0257
2023-05-12 2023-03-31 13F MARATHON PETROLEUM CORP COM US COM 56585A102 12,860 -2,084 -13.95 1,734 -0.35 0.0242
2023-02-10 2022-12-31 13F Marathon Petroleum COM 56585A102 14,944 339 2.32 1,739 19.93 0.0235
2022-11-09 2022-09-30 13F Marathon Petroleum COM 56585A102 14,605 6,128 72.29 1,450 108.03 0.0212
2022-08-16 2022-06-30 13F Marathon Petroleum COM 56585A102 8,477 1,203 16.54 697 12.06 0.0107
2022-05-13 2022-03-31 13F Marathon Petroleum COM 56585A102 7,274 76 1.06 622 34.92 0.0083
2022-02-15 2021-12-31 13F Marathon Petroleum COM 56585A102 7,198 -726 -9.16 461 -5.92 0.0076
2021-11-09 2021-09-30 13F Marathon Petroleum COM 56585A102 7,924 824 11.61 490 14.22 0.0063
2021-08-13 2021-06-30 13F Marathon Petroleum COM 56585A102 7,100 889 14.31 429 29.22 0.0054
2021-05-11 2021-03-31 13F Marathon Petroleum COM 56585A102 6,211 522 9.18 332 41.28 0.0046
2021-02-10 2020-12-31 13F Marathon Petroleum COM 56585A102 5,689 -5,293 -48.20 235 -27.02 0.0034
2020-11-10 2020-09-30 13F Marathon Petroleum COM 56585A102 10,982 4,434 67.72 322 31.43 0.0053
2020-08-05 2020-06-30 13F Marathon Petroleum COM 56585A102 6,548 6,548 245 0.0046
2020-05-11 2020-03-31 13F Marathon Petroleum COM 56585A102 0 -25,540 -100.00 0 -100.00
2020-02-13 2019-12-31 13F Marathon Petroleum COM 56585A102 25,540 579 2.32 1,539 1.52 0.0280
2019-11-01 2019-09-30 13F Marathon Petroleum COM 56585A102 24,961 -794 -3.08 1,516 5.35 0.0302
2019-07-10 2019-06-30 13F Marathon Petroleum COM 56585A102 25,755 -5,537 -17.69 1,439 -23.17 0.0483
2019-05-14 2019-03-31 13F Marathon Petroleum COM 56585A102 31,292 3,408 12.22 1,873 13.86 0.0740
2019-02-14 2018-12-31 13F Marathon Petroleum COM 56585A102 27,884 18,061 183.86 1,645 109.55 0.0702
2018-11-13 2018-09-30 13F Marathon Petroleum COM 56585A102 9,823 299 3.14 785 17.51 0.0278
2018-08-14 2018-06-30 13F Marathon Petroleum COM 56585A102 9,524 -1,555 -14.04 668 -17.53 0.0256
2018-05-11 2018-03-31 13F Marathon Petroleum COM 56585A102 11,079 -1,636 -12.87 810 -3.46 0.0311
2018-02-13 2017-12-31 13F Marathon Petroleum COM 56585A102 12,715 -116 -0.90 839 16.53 0.0316
2017-11-13 2017-09-30 13F Marathon Petroleum COM 56585A102 12,831 -43,770 -77.33 720 -75.69 0.0277
2017-08-04 2017-06-30 13F Marathon Petroleum COM 56585A102 56,601 95 0.17 2,962 3.71 0.1162
2017-05-11 2017-03-31 13F Marathon Petroleum COM 56585A102 56,506 -10,571 -15.76 2,856 -15.43 0.1138
2017-02-15 2016-12-31 13F Marathon Petroleum COM 56585A102 67,077 -2,350 -3.38 3,377 19.84 0.1397
2016-11-15 2016-09-30 13F/A-1 Marathon Petroleum COM 56585A102 69,427 -1,273 -1.80 2,818 4.99 0.1146
2016-11-14 2016-09-30 13F Marathon Petroleum COM 56585A102 70,700 0 2,684 0.1095
2016-08-01 2016-06-30 13F Marathon Petroleum COM 56585A102 70,700 -9,943 -12.33 2,684 -10.47 0.1095
2016-05-13 2016-03-31 13F Marathon Petroleum COM 56585A102 80,643 4,118 5.38 2,998 -24.43 0.1221
2016-02-12 2015-12-31 13F Marathon Petroleum COM 56585A102 76,525 -15,491 -16.84 3,967 -6.94 0.1565
2015-11-12 2015-09-30 13F Marathon Petroleum COM 56585A102 92,016 -14,806 -13.86 4,263 -23.71 0.1652
2015-08-13 2015-06-30 13F Marathon Petroleum COM 56585A102 106,822 50,714 90.39 5,588 -2.73 0.1849
2015-05-12 2015-03-31 13F Marathon Petroleum COM 56585A102 56,108 -4,170 -6.92 5,745 5.59 0.1855
2015-02-10 2014-12-31 13F Marathon Petroleum COM 56585A102 60,278 60,278 5,441 0.1759
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.