Marathon Petroleum Corporation
US ˙ NYSE ˙ US56585A1025

SecurityMPC / Marathon Petroleum Corporation
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership33,092 shares
Latest Disclosed Value $ 8,083,433
Janus Henderson Group Plc reports 76.69% increase in ownership of MPC / Marathon Petroleum Corporation

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 33,092 shares of Marathon Petroleum Corporation (US:MPC) valued at $8,080,405 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 18,729 shares of Marathon Petroleum Corporation. This represents a change in shares of 76.69% during the quarter. The current value of the position is $8,842,513 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)
2026-05-18 2026-03-31 13F/A-1 MARATHON PETE COM 56585A102 33,092 14,363 76.69 8,083 165.45 0.0014
2026-05-15 2026-03-31 13F MARATHON PETE COM 56585A102 33,092 14,363 8,083 0.0015
2026-02-17 2025-12-31 13F MARATHON PETE COM 56585A102 18,729 -369,683 -95.18 3,045 -95.93 0.0014
2025-11-14 2025-09-30 13F MARATHON PETE COM 56585A102 388,412 -49,588 -11.32 74,868 2.91 0.0342
2025-08-14 2025-06-30 13F MARATHON PETE COM 56585A102 438,000 -279,259 -38.93 72,749 -29.61 0.0357
2025-05-15 2025-03-31 13F MARATHON PETE COM 56585A102 717,259 -20,648 -2.80 103,347 0.39 0.0566
2025-02-14 2024-12-31 13F MARATHON PETE COM 56585A102 737,907 -35,291 -4.56 102,944 -18.27 0.0523
2024-11-14 2024-09-30 13F MARATHON PETE COM 56585A102 773,198 -161,122 -17.24 125,960 -22.29 0.0645
2024-08-14 2024-06-30 13F MARATHON PETE COM 56585A102 934,320 -298,159 -24.19 162,084 -34.73 0.0868
2024-05-15 2024-03-31 13F MARATHON PETE COM 56585A102 1,232,479 -44,387 -3.48 248,337 31.10 0.1355
2024-02-14 2023-12-31 13F MARATHON PETE COM 56585A102 1,276,866 -190,984 -13.01 189,427 -14.74 0.1130
2023-11-14 2023-09-30 13F MARATHON PETE COM 56585A102 1,467,850 -282,885 -16.16 222,168 8.83 0.1455
2023-08-14 2023-06-30 13F MARATHON PETE COM 56585A102 1,750,735 -73 -0.00 204,150 -13.50 0.1270
2023-05-15 2023-03-31 13F MARATHON PETE COM 56585A102 1,750,808 583,446 49.98 236,021 73.71 0.1556
2023-02-14 2022-12-31 13F MARATHON PETE COM 56585A102 1,167,362 -146,376 -11.14 135,871 4.12 0.0971
2023-01-13 2022-09-30 13F/A-1 MARATHON PETE COM 56585A102 1,313,738 -211,492 -13.87 130,496 4.07 0.0978
2022-11-14 2022-09-30 13F MARATHON PETE COM 56585A102 1,313,738 -211,492 130,496 0.0977
2022-08-15 2022-06-30 13F MARATHON PETE COM 56585A102 1,525,230 -502,907 -24.80 125,388 -27.69 0.0865
2022-05-16 2022-03-31 13F MARATHON PETE COM 56585A102 2,028,137 -14,910 -0.73 173,405 32.64 0.0837
2022-02-14 2021-12-31 13F MARATHON PETE COM 56585A102 2,043,047 -1,281,472 -38.55 130,734 -36.38 0.0545
2021-11-16 2021-09-30 13F MARATHON PETE COM 56585A102 3,324,519 457,797 15.97 205,486 18.64 0.0899
2021-08-16 2021-06-30 13F MARATHON PETE COM 56585A102 2,866,722 757,914 35.94 173,207 53.55 0.0741
2021-05-17 2021-03-31 13F MARATHON PETE COM 56585A102 2,108,808 1,359,251 181.34 112,800 263.86 0.0515
2021-02-16 2020-12-31 13F MARATHON PETE COM 56585A102 749,557 -87,667 -10.47 31,001 26.21 0.0144
2020-11-16 2020-09-30 13F MARATHON PETE COM 56585A102 837,224 -51,879 -5.83 24,564 -26.09 0.0128
2020-08-14 2020-06-30 13F MARATHON PETE COM 56585A102 889,103 -143,182 -13.87 33,233 36.31 0.0187
2020-05-14 2020-03-31 13F MARATHON PETE COM 56585A102 1,032,285 -237,281 -18.69 24,381 -68.12 0.0168
2020-02-18 2019-12-31 13F MARATHON PETE COM 56585A102 1,269,566 -368,555 -22.50 76,488 -23.14 0.0392
2019-11-14 2019-09-30 13F MARATHON PETE COM 56585A102 1,638,121 -593,588 -26.60 99,515 -20.20 0.0539
2019-07-31 2019-06-30 13F MARATHON PETE COM 56585A102 2,231,709 396,343 21.59 124,709 13.53 0.0679
2019-04-30 2019-03-31 13F MARATHON PETE COM 56585A102 1,835,366 -1,279,631 -41.08 109,848 -40.24 0.0609
2019-02-06 2018-12-31 13F MARATHON PETE COM 56585A102 3,114,997 1,017,935 48.54 183,815 9.57 0.1172
2018-11-09 2018-09-30 13F MARATHON PETE COM 56585A102 2,097,062 153,893 7.92 167,762 23.05 0.0896
2018-08-10 2018-06-30 13F MARATHON PETE COM 56585A102 1,943,169 858,626 79.17 136,334 71.94 0.0777
2018-05-14 2018-03-31 13F MARATHON PETE COM 56585A102 1,084,543 684,639 171.20 79,293 200.51 0.0467
2018-03-12 2017-12-31 13F/A-1 MARATHON PETE COM 56585A102 399,904 -181,188 -31.18 26,386 -19.03 0.0162
2018-02-09 2017-12-31 13F MARATHON PETE COM 56585A102 399,904 -181,188 26,386
2017-11-14 2017-09-30 13F MARATHON PETE COM 56585A102 581,092 -22,076 -3.66 32,588 3.24 0.0209
2017-08-17 2017-06-30 13F/A-1 MARATHON PETE COM 56585A102 603,168 536,795 808.76 31,565 840.83 0.0215
2017-08-14 2017-06-30 13F MARATHON PETE COM 56585A102 603,168 536,795 31,565
2017-05-03 2017-03-31 13F MARATHON PETE COM 56585A102 66,373 -17,494 -20.86 3,355 -20.57 0.0236
2017-01-30 2016-12-31 13F MARATHON PETE COM 56585A102 83,867 14,179 20.35 4,224 49.36 0.0312
2016-10-24 2016-09-30 13F MARATHON PETE COM 56585A102 69,688 -7,145 -9.30 2,828 -3.05 0.0208
2016-07-29 2016-06-30 13F MARATHON PETE COM 56585A102 76,833 -9,249 -10.74 2,917 -8.79 0.0243
2016-05-12 2016-03-31 13F MARATHON PETE COM 56585A102 86,082 200 0.23 3,198 -28.17 0.0259
2016-02-03 2015-12-31 13F MARATHON PETE COM 56585A102 85,882 2,600 3.12 4,452 15.43 0.0357
2015-11-16 2015-09-30 13F MARATHON PETE COM 56585A102 83,282 8,600 11.52 3,857 -1.25 0.0340
2015-08-17 2015-06-30 13F MARATHON PETE COM 56585A102 74,682 37,341 100.00 3,906 2.17 0.0307
2015-06-02 2015-03-31 13F/A-1 MARATHON PETE COM 56585A102 37,341 140 0.38 3,823 13.88 0.0295
2015-05-15 2015-03-31 13F MARATHON PETE COM 56585A102 37,341 3,823
2015-02-12 2014-12-31 13F MARATHON PETE COM 56585A102 37,201 -7,038 -15.91 3,357 -10.36 0.0242
2014-11-12 2014-09-30 13F MARATHON PETE COM 56585A102 44,239 0 0.00 3,745 8.39 0.0352
2014-08-13 2014-06-30 13F MARATHON PETE COM 56585A102 44,239 0 0.00 3,455 -10.28 0.0323
2014-05-08 2014-03-31 13F MARATHON PETE COM 56585A102 44,239 5,625 14.57 3,851 8.69 0.0375
2014-01-14 2013-12-31 13F MARATHON PETE COM 56585A102 38,614 0 0.00 3,543 42.58 0.0358
2013-11-12 2013-09-30 13F MARATHON PETE COM 56585A102 38,614 0 0.00 2,485 -8.57 0.0274
2013-08-15 2013-06-30 13F MARATHON PETE COM 56585A102 38,614 38,614 2,718 0.0318
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.