Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionMassmutual Trust Co Fsb/adv
Latest Disclosed Ownership1,248 shares
Latest Disclosed Value $ 304,737
Massmutual Trust Co Fsb/adv reports 8.57% decrease in ownership of MPC / Marathon Petroleum Corporation

On April 13, 2026 - Massmutual Trust Co Fsb/adv filed a 13F-HR form disclosing ownership of 1,248 shares of Marathon Petroleum Corporation (MX:MPC) valued at $304,737 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 7, 2026 disclosing 1,365 shares of Marathon Petroleum Corporation. This represents a change in shares of -8.57% 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-04-13 2026-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,248 -117 -8.57 305 37.56 0.0083
2026-01-07 2025-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,365 -35 -2.50 222 -17.84 0.0057
2025-10-22 2025-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,400 -74 -5.02 270 10.25 0.0069
2025-07-09 2025-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,474 264 21.82 245 38.64 0.0065
2025-04-01 2025-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,210 134 12.45 176 17.33 0.0051
2025-01-16 2024-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,076 -146 -11.95 150 -24.62 0.0042
2024-10-02 2024-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,222 47 4.00 199 -1.97 0.0057
2024-07-02 2024-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,175 92 8.49 204 -6.88 0.0062
2024-04-09 2024-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,083 -2,664 -71.10 218 -60.72 0.0068
2024-01-03 2023-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 3,747 -1,146 -23.42 556 -25.00 0.0186
2023-10-04 2023-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 4,893 -100 -2.00 741 27.15 0.0273
2023-08-02 2023-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 4,993 269 5.69 582 -8.49 0.0209
2023-04-11 2023-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 4,724 273 6.13 637 0.0243
2023-01-06 2022-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 4,451 4,040 982.97 1 0.0213
2022-10-07 2022-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 411 -1,417 -77.52 0 0.0019
2022-07-07 2022-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,828 -16 -0.87 0 0.0065
2022-04-08 2022-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,844 2 0.11 0 0.0060
2022-02-09 2021-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,842 46 2.56 0 0.0044
2021-11-12 2021-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,796 -62 -3.34 0 0.0046
2021-08-16 2021-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,858 119 6.84 0 0.0048
2021-05-17 2021-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,739 33 1.93 0 0.0044
2021-02-16 2020-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,706 0 0.00 0 0.0036
2020-11-13 2020-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,706 0 0.00 0 -100.00 0.0029
2020-08-13 2020-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 1,706 -2,300 -57.41 64 -32.63 0.0041
2020-05-15 2020-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 4,006 -57,595 -93.50 95 -97.44 0.0076
2020-05-15 2019-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 61,601 967 1.59 3,711 0.73 0.2292
2019-11-14 2019-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 60,634 25,167 70.96 3,684 85.87 0.2467
2019-08-14 2019-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 35,467 259 0.74 1,982 -5.93 0.1370
2019-05-15 2019-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 35,208 4,910 16.21 2,107 17.91 0.1519
2019-02-26 2018-12-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 30,298 4,362 16.82 1,788 -13.84 0.1530
2018-11-09 2018-09-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 25,936 1,740 7.19 2,074 22.22 0.1539
2018-08-20 2018-06-30 13F Marathon Petroleum Common / Ordinary Stock 56585A102 24,196 23,974 10,799.10 1,698 10,506.25 0.1355
2018-05-21 2018-03-31 13F Marathon Petroleum Common / Ordinary Stock 56585A102 222 -933 -80.78 16 -78.95 0.0013
2018-03-01 2017-12-31 13F/A-1 Marathon Petroleum Common / Ordinary Stock 56585A102 1,155 908 367.61 76 484.62 0.0063
2018-02-21 2017-12-31 13F Public Storage Closed-end REIT 56585A102 36 -211 8
2018-02-13 2017-09-30 13F Marathon Petroleum common 56585A102 247 0 0.00 14 8.33 0.0011
2017-08-14 2017-06-30 13F Marathon Petroleum common 56585A102 247 -420 -62.97 13 -63.64 0.0012
2017-05-02 2017-03-31 13F Marathon Petroleum common 56585A102 667 117 21.27 34 22.22 0.0032
2017-02-13 2016-12-31 13F Marathon Petroleum common 56585A102 550 -600 -52.17 28 -37.21 0.0034
2016-08-10 2016-06-30 13F MARATHON PETROLEUM common 56585A102 1,150 150 15.00 44 16.22 0.0055
2016-05-10 2016-03-31 13F MARATHON PETROLEUM common 56585A102 1,000 -200 -16.67 37 -40.32 0.0050
2016-02-12 2015-12-31 13F MARATHON PETROLEUM common 56585A102 1,200 1,200 0.00 62 0.0089
2015-11-04 2015-09-30 13F MARATHON PETROLEUM common 56585A102 0 -100 -100.00 0 -100.00
2015-07-29 2015-06-30 13F MARATHON PETROLEUM common 56585A102 100 100 0.00 8 0.0017
2015-05-11 2015-03-31 13F MARATHON PETROLEUM common 56585A102 0 0 0 0.0000
2015-02-05 2014-12-31 13F MARATHON PETROLEUM common 56585A102 0 0 0 0.0000
2014-11-04 2014-09-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 0 -100 -100.00 0 -100.00
2014-07-09 2014-06-30 13F MARATHON PETROLEUM COMMON STOCK 56585A102 100 100 8 0.0031
2014-05-15 2014-03-31 13F MARATHON PETROLEUM common 56585A102 0 -7 -100.00 0 -100.00 0.0000
2014-02-14 2013-12-31 13F/A-1 MARATHON PETROLEUM COMMON STOCK 56585A102 7 7 1 0.0006
2014-02-13 2013-12-31 13F MARATHON PETROLEUM COMMON STOCK 56585A102 7 1 0.0006
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.