Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionConning Inc.
Latest Disclosed Ownership1,413 shares
Latest Disclosed Value $ 345,026
Conning Inc. reports 17.27% decrease in ownership of MPC / Marathon Petroleum Corporation

On April 30, 2026 - Conning Inc. filed a 13F-HR form disclosing ownership of 1,413 shares of Marathon Petroleum Corporation (MX:MPC) valued at $345,026 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 1,708 shares of Marathon Petroleum Corporation. This represents a change in shares of -17.27% 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)
2026-04-30 2026-03-31 13F MARATHON PETE COM 56585A102 1,413 -295 -17.27 345 24.55 0.0115
2026-02-05 2025-12-31 13F MARATHON PETE COM 56585A102 1,708 -854 -33.33 278 -43.81 0.0093
2025-10-28 2025-09-30 13F MARATHON PETE COM 56585A102 2,562 0 0.00 494 16.00 0.0164
2025-07-24 2025-06-30 13F MARATHON PETE COM 56585A102 2,562 -100 -3.76 426 9.82 0.0146
2025-04-29 2025-03-31 13F MARATHON PETE COM 56585A102 2,662 -454 -14.57 388 -10.83 0.0136
2025-01-28 2024-12-31 13F MARATHON PETE COM 56585A102 3,116 -766 -19.73 435 -31.33 0.0152
2024-10-29 2024-09-30 13F MARATHON PETE COM 56585A102 3,882 -35 -0.89 632 -6.92 0.0209
2024-07-26 2024-06-30 13F MARATHON PETE COM 56585A102 3,917 -5 -0.13 680 -14.05 0.0245
2024-04-26 2024-03-31 13F MARATHON PETE COM 56585A102 3,922 -100 -2.49 790 32.55 0.0259
2024-01-30 2023-12-31 13F MARATHON PETE COM 56585A102 4,022 -25 -0.62 597 -2.61 0.0208
2023-10-26 2023-09-30 13F MARATHON PETE COM 56585A102 4,047 60 1.50 612 31.90 0.0223
2023-07-21 2023-06-30 13F MARATHON PETE COM 56585A102 3,987 -1,604 -28.69 465 -38.38 0.0156
2023-04-27 2023-03-31 13F MARATHON PETE COM 56585A102 5,591 -981 -14.93 754 -1.44 0.0252
2023-02-08 2022-12-31 13F MARATHON PETE COM 56585A102 6,572 186 2.91 765 20.50 0.0249
2022-10-31 2022-09-30 13F MARATHON PETE COM 56585A102 6,386 -932 -12.74 634 5.32 0.0225
2022-07-20 2022-06-30 13F MARATHON PETE COM 56585A102 7,318 -48 -0.65 602 -4.44 0.0180
2022-05-02 2022-03-31 13F MARATHON PETE COM 56585A102 7,366 875 13.48 630 51.81 0.0172
2022-01-27 2021-12-31 13F MARATHON PETE COM 56585A102 6,491 -1,010 -13.46 415 -10.56 0.0111
2021-11-05 2021-09-30 13F MARATHON PETE COM 56585A102 7,501 -490 -6.13 464 -3.93 0.0133
2021-07-29 2021-06-30 13F MARATHON PETE COM 56585A102 7,991 -767 -8.76 483 3.21 0.0140
2021-04-23 2021-03-31 13F MARATHON PETE COM 56585A102 8,758 -710 -7.50 468 19.39 0.0141
2021-01-28 2020-12-31 13F MARATHON PETE COM 56585A102 9,468 1,391 17.22 392 65.40 0.0124
2020-10-21 2020-09-30 13F MARATHON PETE COM 56585A102 8,077 220 2.80 237 -19.39 0.0083
2020-08-07 2020-06-30 13F MARATHON PETE COM 56585A102 7,857 -1,878 -19.29 294 27.83 0.0109
2020-04-29 2020-03-31 13F MARATHON PETE COM 56585A102 9,735 -188 -1.89 230 -61.54 0.0098
2020-01-29 2019-12-31 13F MARATHON PETE COM 56585A102 9,923 -180 -1.78 598 -2.61 0.0196
2019-10-30 2019-09-30 13F MARATHON PETE COM 56585A102 10,103 -729,351 -98.63 614 -98.51 0.0213
2019-07-25 2019-06-30 13F MARATHON PETE COM 56585A102 739,454 145,272 24.45 41,321 16.19 1.3669
2019-04-22 2019-03-31 13F MARATHON PETE COM 56585A102 594,182 579,633 3,984.01 35,562 4,039.93 1.1116
2019-01-29 2018-12-31 13F MARATHON PETE COM 56585A102 14,549 2,046 16.36 859 -14.10 0.0292
2018-10-26 2018-09-30 13F MARATHON PETE COM 56585A102 12,503 -423,586 -97.13 1,000 -96.73 0.0297
2018-07-25 2018-06-30 13F MARATHON PETE COM 56585A102 436,089 -68,798 -13.63 30,596 -17.11 0.9330
2018-05-03 2018-03-31 13F MARATHON PETE COM 56585A102 504,887 58,777 13.18 36,912 25.41 1.1883
2018-01-30 2017-12-31 13F MARATHON PETE COM 56585A102 446,110 -76,983 -14.72 29,434 0.34 0.9716
2017-10-20 2017-09-30 13F MARATHON PETE COM 56585A102 523,093 42,102 8.75 29,335 16.55 0.9984
2017-08-03 2017-06-30 13F MARATHON PETE COM 56585A102 480,991 467,530 3,473.22 25,170 3,601.47 0.9138
2017-04-27 2017-03-31 13F MARATHON PETE COM 56585A102 13,461 -259 -1.89 680 -1.59 0.0251
2017-02-02 2016-12-31 13F MARATHON PETE COM 56585A102 13,720 180 1.33 691 25.64 0.0276
2016-10-25 2016-09-30 13F MARATHON PETE COM 56585A102 13,540 -50 -0.37 550 6.59 0.0219
2016-07-26 2016-06-30 13F MARATHON PETE COM 56585A102 13,590 10 0.07 516 2.18 0.0213
2016-04-26 2016-03-31 13F MARATHON PETE COM 56585A102 13,580 210 1.57 505 -27.13 0.0212
2016-02-04 2015-12-31 13F MARATHON PETE COM 56585A102 13,370 -660 -4.70 693 6.62 0.0296
2015-10-23 2015-09-30 13F MARATHON PETE COM 56585A102 14,030 -1,680 -10.69 650 -20.92 0.0286
2015-08-03 2015-06-30 13F MARATHON PETE COM 56585A102 15,710 7,675 95.52 822 -0.12 0.0337
2015-04-24 2015-03-31 13F MARATHON PETE COM 56585A102 8,035 -140 -1.71 823 11.52 0.0350
2015-02-13 2014-12-31 13F MARATHON PETE COM 56585A102 8,175 -290 -3.43 738 2.93 0.0360
2014-11-07 2014-09-30 13F MARATHON PETE COM 56585A102 8,465 -700 -7.64 717 0.14 0.0376
2014-07-25 2014-06-30 13F MARATHON PETE COM 56585A102 9,165 -860 -8.58 716 -17.98 0.0381
2014-04-25 2014-03-31 13F MARATHON PETE COM 56585A102 10,025 50 0.50 873 -4.59 0.0513
2014-02-04 2013-12-31 13F MARATHON PETE COM 56585A102 9,975 1,540 18.26 915 68.51 0.0567
2013-11-04 2013-09-30 13F MARATHON PETE COM 56585A102 8,435 60 0.72 543 -8.74 0.0419
2013-08-13 2013-06-30 13F MARATHON PETE COM 56585A102 8,375 8,375 595 0.0492
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.