Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionKorea Investment CORP
Latest Disclosed Ownership322,515 shares
Latest Disclosed Value $ 78,751,713
Korea Investment CORP reports 3.96% increase in ownership of MPC / Marathon Petroleum Corporation

On May 13, 2026 - Korea Investment CORP filed a 13F-HR form disclosing ownership of 322,515 shares of Marathon Petroleum Corporation (MX:MPC) valued at $78,751,713 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 310,221 shares of Marathon Petroleum Corporation. This represents a change in shares of 3.96% 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)
2026-05-13 2026-03-31 13F MARATHON PETE COM 56585A102 322,515 12,294 3.96 78,752 56.09 0.1631
2026-02-13 2025-12-31 13F MARATHON PETE COM 56585A102 310,221 87,255 39.13 50,451 17.40 0.0993
2025-11-13 2025-09-30 13F MARATHON PETE COM 56585A102 222,966 -72,616 -24.57 42,974 -12.47 0.0884
2025-08-13 2025-06-30 13F MARATHON PETE COM 56585A102 295,582 45,981 18.42 49,099 35.02 0.1092
2025-05-14 2025-03-31 13F MARATHON PETE COM 56585A102 249,601 -7,327 -2.85 36,364 1.46 0.0881
2025-02-12 2024-12-31 13F MARATHON PETE COM 56585A102 256,928 13,362 5.49 35,841 -9.67 0.0850
2024-11-13 2024-09-30 13F MARATHON PETE COM 56585A102 243,566 -44,514 -15.45 39,679 -20.60 0.0942
2024-08-13 2024-06-30 13F MARATHON PETE COM 56585A102 288,080 -22,731 -7.31 49,976 -20.20 0.1259
2024-05-14 2024-03-31 13F MARATHON PETE COM 56585A102 310,811 -148,023 -32.26 62,628 -8.00 0.1589
2024-02-13 2023-12-31 13F MARATHON PETE COM 56585A102 458,834 -203,432 -30.72 68,073 -32.08 0.1787
2023-11-13 2023-09-30 13F MARATHON PETE COM 56585A102 662,266 253,321 61.95 100,227 110.20 0.2952
2023-08-11 2023-06-30 13F MARATHON PETE COM 56585A102 408,945 139,753 51.92 47,683 31.37 0.1340
2023-05-12 2023-03-31 13F MARATHON PETE COM 56585A102 269,192 -79,117 -22.71 36,295 -10.47 0.1057
2023-02-13 2022-12-31 13F MARATHON PETE COM 56585A102 348,309 120,873 53.15 40,540 79.45 0.1274
2022-11-10 2022-09-30 13F MARATHON PETE COM 56585A102 227,436 40,873 21.91 22,591 47.30 0.0695
2022-08-12 2022-06-30 13F MARATHON PETE COM 56585A102 186,563 -39,437 -17.45 15,337 -20.63 0.0469
2022-05-13 2022-03-31 13F MARATHON PETE COM 56585A102 226,000 78,600 53.32 19,323 104.87 0.0478
2022-02-09 2021-12-31 13F MARATHON PETE COM 56585A102 147,400 8,300 5.97 9,432 9.70 0.0245
2021-11-12 2021-09-30 13F MARATHON PETE COM 56585A102 139,100 -4,300 -3.00 8,598 -0.76 0.0256
2021-08-12 2021-06-30 13F MARATHON PETE COM 56585A102 143,400 -123,236 -46.22 8,664 -39.25 0.0248
2021-05-13 2021-03-31 13F MARATHON PETE COM 56585A102 266,636 -55,200 -17.15 14,262 7.14 0.0450
2021-02-10 2020-12-31 13F MARATHON PETE COM 56585A102 321,836 31,400 10.81 13,311 56.21 0.0400
2020-11-12 2020-09-30 13F MARATHON PETE COM 56585A102 290,436 113,350 64.01 8,521 28.74 0.0301
2020-08-12 2020-06-30 13F MARATHON PETE COM 56585A102 177,086 -16,900 -8.71 6,619 44.46 0.0243
2020-05-14 2020-03-31 13F MARATHON PETE COM 56585A102 193,986 151,900 360.93 4,582 80.68 0.0201
2020-02-11 2019-12-31 13F MARATHON PETE COM 56585A102 42,086 -1,800 -4.10 2,536 -4.88 0.0092
2019-11-12 2019-09-30 13F MARATHON PETE COM 56585A102 43,886 -53,200 -54.80 2,666 -50.86 0.0113
2019-08-12 2019-06-30 13F MARATHON PETE COM 56585A102 97,086 -24,517 -20.16 5,425 -25.46 0.0233
2019-05-15 2019-03-31 13F MARATHON PETE COM 56585A102 121,603 -171,591 -58.52 7,278 -57.93 0.0328
2019-02-13 2018-12-31 13F MARATHON PETE COM 56585A102 293,194 83,811 40.03 17,301 3.33 0.0940
2018-11-13 2018-09-30 13F MARATHON PETE COM 56585A102 209,383 -68,034 -24.52 16,744 -13.97 0.0772
2018-08-13 2018-06-30 13F MARATHON PETE COM 56585A102 277,417 -32,200 -10.40 19,464 -14.01 0.0887
2018-05-09 2018-03-31 13F MARATHON PETE COM 56585A102 309,617 -61,683 -16.61 22,636 -7.60 0.1053
2018-02-12 2017-12-31 13F MARATHON PETE COM 56585A102 371,300 28,500 8.31 24,498 27.43 0.1115
2017-10-25 2017-09-30 13F MARATHON PETE COM 56585A102 342,800 -10,500 -2.97 19,224 3.98 0.0888
2017-07-31 2017-06-30 13F MARATHON PETE COM 56585A102 353,300 -39,828 -10.13 18,488 -6.95 0.0862
2017-04-25 2017-03-31 13F MARATHON PETE COM 56585A102 393,128 53,304 15.69 19,869 16.13 0.0986
2017-02-13 2016-12-31 13F MARATHON PETE COM 56585A102 339,824 -69,176 -16.91 17,110 3.07 0.0822
2016-11-09 2016-09-30 13F MARATHON PETE COM 56585A102 409,000 116,100 39.64 16,601 49.32 0.0885
2016-08-12 2016-06-30 13F MARATHON PETE COM 56585A102 292,900 -89,000 -23.30 11,118 -21.70 0.0662
2016-05-12 2016-03-31 13F MARATHON PETE COM 56585A102 381,900 211,400 123.99 14,199 60.66 0.1038
2016-02-01 2015-12-31 13F MARATHON PETE COM 56585A102 170,500 -14,300 -7.74 8,838 3.24 0.0616
2015-11-12 2015-09-30 13F MARATHON PETE COM 56585A102 184,800 -3,400 -1.81 8,561 -13.04 0.0682
2015-08-13 2015-06-30 13F MARATHON PETE COM 56585A102 188,200 94,100 100.00 9,845 2.18 0.0839
2015-05-11 2015-03-31 13F MARATHON PETE COM 56585A102 94,100 700 0.75 9,635 14.29 0.0751
2015-02-12 2014-12-31 13F MARATHON PETE COM 56585A102 93,400 -40,600 -30.30 8,430 -25.70 0.0692
2014-11-14 2014-09-30 13F MARATHON PETE COM 56585A102 134,000 12,700 10.47 11,346 19.81 0.0926
2014-08-14 2014-06-30 13F MARATHON PETE COM 56585A102 121,300 -64,300 -34.64 9,470 -41.38 0.0788
2014-05-14 2014-03-31 13F MARATHON PETE COM 56585A102 185,600 42,600 29.79 16,155 23.16 0.1430
2014-02-06 2013-12-31 13F MARATHON PETE COM 56585A102 143,000 -64,800 -31.18 13,117 -1.86 0.1240
2013-11-07 2013-09-30 13F/A-1 MARATHON PETE COM 56585A102 207,800 31,800 18.07 13,366 6.87 0.1420
2013-11-05 2013-09-30 13F MARATHON PETE COM 56585A102 138,900 8,934
2013-08-08 2013-06-30 13F MARATHON PETE COM 56585A102 176,000 176,000 12,507 0.1499
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.