Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionRobeco Institutional Asset Management B.V.
Latest Disclosed Ownership352,477 shares
Latest Disclosed Value $ 86,067,832
Robeco Institutional Asset Management B.V. reports 50.35% increase in ownership of MPC / Marathon Petroleum Corporation

On April 21, 2026 - Robeco Institutional Asset Management B.V. filed a 13F-HR form disclosing ownership of 352,477 shares of Marathon Petroleum Corporation (MX:MPC) valued at $86,067,832 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 23, 2026 disclosing 234,430 shares of Marathon Petroleum Corporation. This represents a change in shares of 50.35% 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)
2026-04-21 2026-03-31 13F MARATHON PETE COM 56585A102 352,477 118,047 50.35 86,068 125.75 0.1227
2026-01-23 2025-12-31 13F MARATHON PETE COM 56585A102 234,430 100,511 75.05 38,125 47.71 0.0543
2025-10-22 2025-09-30 13F MARATHON PETE COM 56585A102 133,919 4,442 3.43 25,812 20.01 0.0374
2025-07-18 2025-06-30 13F MARATHON PETE COM 56585A102 129,477 108,016 503.31 21,507 588.00 0.0348
2025-04-23 2025-03-31 13F MARATHON PETE COM 56585A102 21,461 -39,579 -64.84 3,127 -63.29 0.0061
2025-01-23 2024-12-31 13F MARATHON PETE COM 56585A102 61,040 -181,476 -74.83 8,515 -78.45 0.0161
2024-10-29 2024-09-30 13F MARATHON PETE COM 56585A102 242,516 -283,593 -53.90 39,508 -56.71 0.0785
2024-07-23 2024-06-30 13F MARATHON PETE COM 56585A102 526,109 -125,252 -19.23 91,269 -30.46 0.1964
2024-04-24 2024-03-31 13F MARATHON PETE COM 56585A102 651,361 -63,656 -8.90 131,249 23.73 0.2852
2024-02-14 2023-12-31 13F/A-1 MARATHON PETE COM 56585A102 715,017 -151,333 -17.47 106,080 -19.09 0.2572
2024-02-08 2023-12-31 13F MARATHON PETE COM 56585A102 389,638 -476,712 715 0.1339
2023-10-24 2023-09-30 13F MARATHON PETE COM 56585A102 866,350 -30,477 -3.40 131,113 25.38 0.3504
2023-07-24 2023-06-30 13F MARATHON PETE COM 56585A102 896,827 104,297 13.16 104,570 -2.14 0.2742
2023-05-04 2023-03-31 13F MARATHON PETE COM 56585A102 792,530 48,218 6.48 106,857 23.35 0.2913
2023-02-07 2022-12-31 13F MARATHON PETE COM 56585A102 744,312 379,615 104.09 86,630 139.14 0.2496
2022-12-01 2022-09-30 13F/A-1 MARATHON PETE COM 56585A102 364,697 202,972 125.50 36,225 172.41 0.1171
2022-10-27 2022-09-30 13F MARATHON PETE COM 56585A102 364,697 202,972 36,225 0.1155
2022-12-01 2022-06-30 13F/A-1 MARATHON PETE COM 56585A102 161,725 -24,833 -13.31 13,298 -16.63 0.0413
2022-07-27 2022-06-30 13F MARATHON PETE COM 56585A102 161,725 -24,833 13,298 0.0407
2022-12-01 2022-03-31 13F/A-1 MARATHON PETE COM 56585A102 186,558 -36,443 -16.34 15,950 11.80 0.0376
2022-04-26 2022-03-31 13F MARATHON PETE COM 56585A102 186,558 -36,443 15,950 0.0371
2022-12-01 2021-12-31 13F/A-1 MARATHON PETE COM 56585A102 223,001 -26,618 -10.66 14,267 -7.52 0.0304
2022-01-31 2021-12-31 13F MARATHON PETE COM 56585A102 223,001 -26,618 14,267 0.0300
2022-12-01 2021-09-30 13F/A-1 MARATHON PETE COM 56585A102 249,619 -7,993 -3.10 15,427 -0.89 0.0342
2021-10-20 2021-09-30 13F MARATHON PETE COM 56585A102 249,619 -7,993 15,427 0.0338
2022-12-01 2021-06-30 13F/A-1 MARATHON PETE COM 56585A102 257,612 45,638 21.53 15,565 37.27 0.0345
2021-07-28 2021-06-30 13F MARATHON PETE COM 56585A102 257,612 45,638 15,565 0.0340
2022-12-01 2021-03-31 13F/A-1 MARATHON PETE COM 56585A102 211,974 -71,488 -25.22 11,339 -3.29 0.0279
2021-04-23 2021-03-31 13F MARATHON PETE COM 56585A102 211,974 -71,488 11,339 0.0276
2022-12-01 2020-12-31 13F/A-1 MARATHON PETE COM 56585A102 283,462 27,069 10.56 11,725 55.88 0.0308
2021-01-28 2020-12-31 13F MARATHON PETE COM 56585A102 283,462 27,069 11,725 0.0304
2021-01-19 2020-09-30 13F/A-1 MARATHON PETE COM 56585A102 256,393 -71,274 -21.75 7,522 -38.59 0.0232
2020-10-29 2020-09-30 13F MARATHON PETE COM 56585A102 256,393 -71,274 7,522 23,230.3841
2021-01-19 2020-06-30 13F/A-1 MARATHON PETE COM 56585A102 327,667 -71,738 -17.96 12,249 29.84 0.0416
2020-07-20 2020-06-30 13F MARATHON PETE COM 56585A102 327,667 -71,738 12,249 41,563.0418
2021-01-19 2020-03-31 13F/A-1 MARATHON PETE COM 56585A102 399,405 169,367 73.63 9,434 -31.93 0.0378
2020-04-30 2020-03-31 13F MARATHON PETE COM 56585A102 399,405 153,227 9,434 37,813.5996
2021-01-19 2019-12-31 13F/A-1 MARATHON PETE COM 56585A102 230,038 -39,157 -14.55 13,859 -15.25 0.0444
2020-02-06 2019-12-31 13F MARATHON PETE COM 56585A102 246,178 -34,567 14,831 47,435.8130
2021-01-19 2019-09-30 13F/A-1 MARATHON PETE COM 56585A102 269,195 7,395 2.82 16,353 11.76 0.0577
2019-10-17 2019-09-30 13F MARATHON PETE COM 56585A102 280,745 12,070 17,055 60,125.8889
2021-01-19 2019-06-30 13F/A-1 MARATHON PETE COM 56585A102 261,800 -26,405 -9.16 14,632 -15.18 0.0517
2019-07-19 2019-06-30 13F MARATHON PETE COM 56585A102 268,675 -19,530 15,016 52,950.3437
2021-01-19 2019-03-31 13F/A-1 MARATHON PETE COM 56585A102 288,205 -67,076 -18.88 17,250 -17.52 0.0634
2019-05-02 2019-03-31 13F MARATHON PETE COM 56585A102 288,205 -71,640 17,250 63,335.8636
2021-01-19 2018-12-31 13F/A-1 MARATHON PETE COM 56585A102 355,281 156,259 78.51 20,915 31.43 0.0939
2019-02-08 2018-12-31 13F MARATHON PETE COM 56585A102 359,845 160,823 21,184 94,956.2302
2021-01-19 2018-09-30 13F/A-1 MARATHON PETE COM 56585A102 199,022 -13,579 -6.39 15,914 6.71 0.0630
2018-10-25 2018-09-30 13F MARATHON PETE COM 56585A102 198,627 -13,974 15,882
2021-01-19 2018-06-30 13F/A-1 MARATHON PETE COM 56585A102 212,601 -147,324 -40.93 14,913 -43.33 0.0679
2018-08-03 2018-06-30 13F MARATHON PETE COM 56585A102 212,601 -147,324 14,913
2021-01-19 2018-03-31 13F/A-1 MARATHON PETE COM 56585A102 359,925 28,040 8.45 26,317 20.17 0.1235
2018-05-07 2018-03-31 13F MARATHON PETE COM 56585A102 359,925 28,040 26,317 123,072.2983
2021-01-19 2017-12-31 13F/A-1 MARATHON PETE COM 56585A102 331,885 32,636 10.91 21,899 30.48 0.1135
2018-01-25 2017-12-31 13F MARATHON PETE COM 56585A102 331,885 32,636 21,899
2021-01-19 2017-09-30 13F/A-1 MARATHON PETE COM 56585A102 299,249 21,460 7.73 16,783 15.44 0.1042
2017-10-17 2017-09-30 13F MARATHON PETE COM 56585A102 299,249 21,460 16,783 103,976.5727
2021-01-19 2017-06-30 13F/A-1 MARATHON PETE COM 56585A102 277,789 68,500 32.73 14,538 37.46 0.0936
2017-08-07 2017-06-30 13F MARATHON PETE COM 56585A102 277,789 60,666 14,538 94,654.0884
2021-01-19 2017-03-31 13F/A-1 MARATHON PETE COM 56585A102 209,289 27,748 15.28 10,576 15.70 0.0704
2017-05-15 2017-03-31 13F MARATHON PETE COM 56585A102 217,123 35,582 10,972 72,875.3614
2017-02-09 2016-12-31 13F MARATHON PETE COM 56585A102 181,541 -22,613 -11.08 9,141 10.31 0.0715
2016-11-07 2016-09-30 13F MARATHON PETE COM 56585A102 204,154 -1,494 -0.73 8,287 6.19 0.0613
2016-07-22 2016-06-30 13F MARATHON PETE COM 56585A102 205,648 -26,231 -11.31 7,804 -9.50 0.0592
2016-05-16 2016-03-31 13F MARATHON PETE COM 56585A102 231,879 61,789 36.33 8,623 -2.21 0.0692
2016-02-08 2015-12-31 13F MARATHON PETE COM 56585A102 170,090 -345,230 -66.99 8,818 -63.07 0.0754
2015-11-12 2015-09-30 13F MARATHON PETE COM 56585A102 515,320 27,286 5.59 23,875 -6.48 0.1819
2015-08-17 2015-06-30 13F MARATHON PETE COM 56585A102 488,034 34,840 7.69 25,530 -44.98 0.1938
2015-04-24 2015-03-31 13F MARATHON PETE COM 56585A102 453,194 36,129 8.66 46,403 23.27 0.3489
2015-02-12 2014-12-31 13F MARATHON PETE COM 56585A102 417,065 18,914 4.75 37,644 11.67 0.2699
2014-11-10 2014-09-30 13F MARATHON PETE COM 56585A102 398,151 12,098 3.13 33,711 11.85 0.2408
2014-08-13 2014-06-30 13F MARATHON PETE COM 56585A102 386,053 322,107 503.72 30,140 441.60 0.2157
2014-05-07 2014-03-31 13F MARATHON PETE COM 56585A102 63,946 35,881 127.85 5,565 116.03 0.0427
2014-02-04 2013-12-31 13F MARATHON PETE COM 56585A102 28,065 -58,127 -67.44 2,576 -53.54 0.0214
2013-11-12 2013-09-30 13F MARATHON PETE COM 56585A102 86,192 -11,392 -11.67 5,544 -20.06 0.0539
2013-08-27 2013-06-30 13F Marathon Petroleum COM 56585A102 97,584 97,584 6,935 0.0702
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.