Marathon Petroleum Corporation
US ˙ NYSE ˙ US56585A1025

SecurityMPC / Marathon Petroleum Corporation
InstitutionAsset Management One Co., Ltd.
Latest Disclosed Ownership123,272 shares
Latest Disclosed Value $ 30,100,557
Asset Management One Co., Ltd. reports 2.74% decrease in ownership of MPC / Marathon Petroleum Corporation

On May 8, 2026 - Asset Management One Co., Ltd. filed a 13F-HR form disclosing ownership of 123,272 shares of Marathon Petroleum Corporation (US:MPC) valued at $30,100,557 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 27, 2026 disclosing 126,749 shares of Marathon Petroleum Corporation. This represents a change in shares of -2.74% during the quarter. The current value of the position is $32,939,511 USD.

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)
2026-05-08 2026-03-31 13F MARATHON PETE COM 56585A102 123,272 -3,477 -2.74 30,101 45.18 0.0888
2026-01-27 2025-12-31 13F MARATHON PETE COM 56585A102 126,749 768 0.61 20,734 -14.61 0.0576
2025-10-22 2025-09-30 13F MARATHON PETE COM 56585A102 125,981 -1,900 -1.49 24,282 14.31 0.0704
2025-07-31 2025-06-30 13F MARATHON PETE COM 56585A102 127,881 -14,902 -10.44 21,242 2.12 0.0666
2025-04-23 2025-03-31 13F MARATHON PETE COM 56585A102 142,783 -594 -0.41 20,802 6.95 0.0719
2025-01-30 2024-12-31 13F MARATHON PETE COM 56585A102 143,377 -7,748 -5.13 19,452 -20.99 0.0668
2024-10-30 2024-09-30 13F MARATHON PETE COM 56585A102 151,125 5,308 3.64 24,620 -2.68 0.0876
2024-07-18 2024-06-30 13F MARATHON PETE COM 56585A102 145,817 -17,176 -10.54 25,296 -22.98 0.0968
2024-05-02 2024-03-31 13F MARATHON PETE COM 56585A102 162,993 -17,301 -9.60 32,843 24.02 0.1266
2024-01-24 2023-12-31 13F MARATHON PETE COM 56585A102 180,294 -12,395 -6.43 26,482 -9.19 0.1066
2023-10-19 2023-09-30 13F MARATHON PETE COM 56585A102 192,689 4,659 2.48 29,162 33.01 0.1298
2023-07-31 2023-06-30 13F MARATHON PETE COM 56585A102 188,030 -18,676 -9.04 21,924 -21.33 0.0928
2023-04-25 2023-03-31 13F MARATHON PETE COM 56585A102 206,706 -11,875 -5.43 27,870 9.74 0.1263
2023-02-06 2022-12-31 13F MARATHON PETE COM 56585A102 218,581 -21,239 -8.86 25,396 6.61 0.1238
2022-11-04 2022-09-30 13F MARATHON PETE COM 56585A102 239,820 -12,149 -4.82 23,821 15.00 0.1212
2022-07-29 2022-06-30 13F MARATHON PETE COM 56585A102 251,969 -18,626 -6.88 20,714 -10.46 0.0973
2022-05-13 2022-03-31 13F MARATHON PETE COM 56585A102 270,595 -18,488 -6.40 23,135 25.14 0.0903
2022-02-09 2021-12-31 13F MARATHON PETE COM 56585A102 289,083 -4,613 -1.57 18,487 1.84 0.0644
2021-11-02 2021-09-30 13F MARATHON PETE COM 56585A102 293,696 -11,936 -3.91 18,153 -1.69 0.0696
2021-08-03 2021-06-30 13F MARATHON PETE COM 56585A102 305,632 -7,315 -2.34 18,465 10.31 0.0687
2021-05-14 2021-03-31 13F MARATHON PETE COM 56585A102 312,947 -7,232 -2.26 16,739 28.30 0.0665
2021-02-12 2020-12-31 13F MARATHON PETE COM 56585A102 320,179 -3,425 -1.06 13,047 37.39 0.0537
2020-11-13 2020-09-30 13F MARATHON PETE COM 56585A102 323,604 -13,939 -4.13 9,496 -24.74 0.0437
2020-08-14 2020-06-30 13F MARATHON PETE COM 56585A102 337,543 -14,546 -4.13 12,617 51.70 0.0620
2020-05-14 2020-03-31 13F MARATHON PETE COM 56585A102 352,089 -5,062 -1.42 8,317 -61.35 0.0486
2020-02-14 2019-12-31 13F MARATHON PETE COM 56585A102 357,151 -8,169 -2.24 21,518 -3.04 0.0970
2019-11-14 2019-09-30 13F MARATHON PETE COM 56585A102 365,320 -3,582 -0.97 22,193 7.64 0.1069
2019-08-14 2019-06-30 13F MARATHON PETE COM 56585A102 368,902 25,603 7.46 20,617 0.35 0.1013
2019-05-15 2019-03-31 13F MARATHON PETE COM 56585A102 343,299 -809,811 -70.23 20,546 -69.80 0.1111
2019-02-13 2018-12-31 13F MARATHON PETE COM 56585A102 1,153,110 369,264 47.11 68,044 8.27 0.1622
2018-11-14 2018-09-30 13F MARATHON PETE COM 56585A102 783,846 -1,221 -0.16 62,849 14.18 0.1290
2018-08-14 2018-06-30 13F MARATHON PETE COM 56585A102 785,067 -26,318 -3.24 55,045 -7.21 0.1203
2018-05-14 2018-03-31 13F MARATHON PETE COM 56585A102 811,385 585 0.07 59,321 10.84 0.1336
2018-02-14 2017-12-31 13F MARATHON PETE COM 56585A102 810,800 3,828 0.47 53,519 18.33 0.1181
2017-11-14 2017-09-30 13F MARATHON PETE COM 56585A102 806,972 -109,419 -11.94 45,228 -5.53 0.1062
2017-08-14 2017-06-30 13F MARATHON PETE COM 56585A102 916,391 -25,891 -2.75 47,878 0.68 0.1222
2017-05-11 2017-03-31 13F MARATHON PETE COM 56585A102 942,282 24,350 2.65 47,555 2.88 0.1249
2017-05-02 2016-12-31 13F/A-1 MARATHON PETE COM 56585A102 917,932 864,777 1,626.90 46,226 2,079.44 0.1181
2017-02-13 2016-12-31 13F MARATHON PETE COM 56585A102 1,044,332 52,590
2016-11-07 2016-09-30 13F MARATHON PETROLEUM Com 56585A102 53,155 -10,689 -16.74 2,121 -11.33 0.0315
2016-08-03 2016-06-30 13F MARATHON PETROLEUM Com 56585A102 63,844 -117,214 -64.74 2,392 -64.31 0.0359
2016-05-05 2016-03-31 13F MARATHON PETROLEUM Com 56585A102 181,058 -78,431 -30.23 6,702 -50.23 0.0978
2016-01-28 2015-12-31 13F MARATHON PETROLEUM Com 56585A102 259,489 50,751 24.31 13,466 39.76 0.2010
2015-11-12 2015-09-30 13F MARATHON PETROLEUM Com 56585A102 208,738 -71,191 -25.43 9,635 -33.90 0.1466
2015-08-06 2015-06-30 13F MARATHON PETROLEUM Com 56585A102 279,929 192,817 221.34 14,576 63.21 0.2020
2015-05-11 2015-03-31 13F MARATHON PETROLEUM Com 56585A102 87,112 54,395 166.26 8,931 200.40 0.1103
2015-02-09 2014-12-31 13F MARATHON PETROLEUM Com 56585A102 32,717 -60,771 -65.00 2,973 -62.41 0.0386
2014-11-05 2014-09-30 13F MARATHON PETROLEUM Com 56585A102 93,488 44,395 90.43 7,908 103.60 0.1092
2014-08-12 2014-06-30 13F MARATHON PETROLEUM Com 56585A102 49,093 -146,863 -74.95 3,884 -77.26 0.0580
2014-05-05 2014-03-31 13F MARATHON PETROLEUM Com 56585A102 195,956 102,123 108.83 17,082 101.32 0.2692
2014-02-05 2013-12-31 13F/A-1 MARATHON PETROLEUM COM 56585A102 93,833 -3,499 -3.59 8,485 35.00 0.1315
2014-01-29 2013-12-31 13F MARATHON PETROLEUM COM 56585A102 93,833 8,485
2014-02-05 2013-09-30 13F/A-1 MARATHON PETROLEUM Com 56585A102 97,332 -75,123 -43.56 6,285 -48.71 0.0946
2013-11-06 2013-09-30 13F MARATHON PETROLEUM Com 56585A102 97,332 6,285
2014-02-12 2013-06-30 13F/A-1 MARATHON PETROLEUM COM 56585A102 172,455 172,455 12,253 0.1990
2013-08-05 2013-06-30 13F MARATHON PETROLEUM Com 56585A102 172,455 12,253
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.