Marathon Petroleum Corporation
MX ˙ BMV ˙ US56585A1025
SecurityMX:MPC / Marathon Petroleum Corporation
InstitutionTranquility Partners, LLC
Latest Disclosed Ownership10,241 shares
Latest Disclosed Value $ 2,500,648
Tranquility Partners, LLC reports 1.06% decrease in ownership of MPC / Marathon Petroleum Corporation

On April 20, 2026 - Tranquility Partners, LLC filed a 13F-HR form disclosing ownership of 10,241 shares of Marathon Petroleum Corporation (MX:MPC) valued at $2,500,648 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 3, 2026 disclosing 10,351 shares of Marathon Petroleum Corporation. This represents a change in shares of -1.06% 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)
2026-04-20 2026-03-31 13F MARATHON PETE COM 56585A102 10,241 -110 -1.06 2,501 48.54 0.9433
2026-02-03 2025-12-31 13F MARATHON PETE COM 56585A102 10,351 -106 -1.01 1,683 -16.48 0.6064
2025-10-30 2025-09-30 13F MARATHON PETE COM 56585A102 10,457 -141 -1.33 2,015 14.49 0.6805
2025-07-25 2025-06-30 13F MARATHON PETE COM 56585A102 10,598 419 4.12 1,760 18.76 0.6287
2025-04-24 2025-03-31 13F MARATHON PETE COM 56585A102 10,179 700 7.38 1,483 10.85 0.5727
2025-01-29 2024-12-31 13F MARATHON PETE COM 56585A102 9,479 -628 -6.21 1,338 -18.77 0.5030
2024-11-07 2024-09-30 13F MARATHON PETE COM 56585A102 10,107 345 3.53 1,646 -2.78 0.5970
2024-07-25 2024-06-30 13F MARATHON PETE COM 56585A102 9,762 220 2.31 1,693 -11.91 0.6515
2024-05-07 2024-03-31 13F MARATHON PETE COM 56585A102 9,542 1,076 12.71 1,923 53.03 0.7431
2024-01-31 2023-12-31 13F MARATHON PETE COM 56585A102 8,466 -1,542 -15.41 1,256 -17.04 0.5266
2023-10-31 2023-09-30 13F MARATHON PETE COM 56585A102 10,008 1,167 13.20 1,515 46.99 0.6493
2023-07-17 2023-06-30 13F MARATHON PETE COM 56585A102 8,841 50 0.57 1,031 -13.08 0.4441
2023-05-08 2023-03-31 13F MARATHON PETE COM 56585A102 8,791 274 3.22 1,185 19.58 0.5647
2023-02-02 2022-12-31 13F MARATHON PETE COM 56585A102 8,517 -231 -2.64 991 14.04 0.5043
2022-11-01 2022-09-30 13F MARATHON PETE COM 56585A102 8,748 -248 -2.76 869 17.43 0.4836
2022-08-01 2022-06-30 13F MARATHON PETE COM 56585A102 8,996 0 0.00 740 -3.77 0.3828
2022-04-29 2022-03-31 13F MARATHON PETE COM 56585A102 8,996 0 0.00 769 33.51 0.3601
2022-01-31 2021-12-31 13F MARATHON PETE COM 56585A102 8,996 -276 -2.98 576 0.52 0.2666
2021-10-20 2021-09-30 13F MARATHON PETE COM 56585A102 9,272 234 2.59 573 4.95 0.2908
2021-07-23 2021-06-30 13F MARATHON PETE COM 56585A102 9,038 -1,782 -16.47 546 -5.70 0.3068
2021-04-30 2021-03-31 13F MARATHON PETE COM 56585A102 10,820 460 4.44 579 35.28 0.3601
2021-01-29 2020-12-31 13F MARATHON PETE COM 56585A102 10,360 577 5.90 428 49.13 0.3024
2020-11-10 2020-09-30 13F MARATHON PETE COM 56585A102 9,783 -4,551 -31.75 287 -46.46 0.2438
2020-07-29 2020-06-30 13F MARATHON PETE COM 56585A102 14,334 -1,444 -9.15 536 43.70 0.5047
2020-04-20 2020-03-31 13F MARATHON PETE COM 56585A102 15,778 -7,159 -31.21 373 -73.01 0.4293
2020-02-03 2019-12-31 13F MARATHON PETE COM 56585A102 22,937 -7,179 -23.84 1,382 -24.48 1.2477
2019-11-14 2019-09-30 13F MARATHON PETE COM 56585A102 30,116 651 2.21 1,830 11.11 1.9395
2019-08-13 2019-06-30 13F MARATHON PETE COM 56585A102 29,465 29,465 1,647 1.7754
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.