MPLX LP - Limited Partnership
US ˙ NYSE ˙ US55336V1008

SecurityMPLX / MPLX LP - Limited Partnership
InstitutionSei Investments Co
Latest Disclosed Ownership21,974 shares
Latest Disclosed Value $ 1,172,752
Sei Investments Co reports 1.43% decrease in ownership of MPLX / MPLX LP - Limited Partnership

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 21,974 shares of MPLX LP - Limited Partnership (US:MPLX) valued at $1,172,752 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 22,293 shares of MPLX LP - Limited Partnership. This represents a change in shares of -1.43% during the quarter. The current value of the position is $1,240,872 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)
2026-02-13 2025-12-31 13F MPLX COM UNIT REP LTD 55336V100 21,974 -319 -1.43 1,173 5.30 0.0012
2025-11-13 2025-09-30 13F MPLX COM UNIT REP LTD 55336V100 22,293 0 0.00 1,114 -3.05 0.0012
2025-08-14 2025-06-30 13F MPLX COM UNIT REP LTD 55336V100 22,293 -489 -2.15 1,148 -5.82 0.0013
2025-05-14 2025-03-31 13F/A-1 MPLX COM UNIT REP LTD 55336V100 22,782 -19,176 -45.70 1,219 -39.29 0.0016
2025-05-13 2025-03-31 13F MPLX COM UNIT REP LTD 55336V100 42,126 168 2,017 0.0022
2025-02-11 2024-12-31 13F MPLX COM UNIT REP LTD 55336V100 41,958 -5,368 -11.34 2,008 -4.56 0.0026
2024-11-12 2024-09-30 13F MPLX COM UNIT REP LTD 55336V100 47,326 -9,818 -17.18 2,104 -13.52 0.0027
2024-08-13 2024-06-30 13F MPLX COM UNIT REP LTD 55336V100 57,144 5,404 10.44 2,434 13.16 0.0034
2024-05-07 2024-03-31 13F MPLX COM UNIT REP LTD 55336V100 51,740 16,637 47.39 2,150 66.93 0.0032
2024-02-14 2023-12-31 13F MPLX COM UNIT REP LTD 55336V100 35,103 5,686 19.33 1,289 23.14 0.0021
2023-11-14 2023-09-30 13F MPLX COM UNIT REP LTD 55336V100 29,417 -22 -0.07 1,046 4.70 0.0019
2023-08-11 2023-06-30 13F MPLX COM UNIT REP LTD 55336V100 29,439 14,832 101.54 999 98.61 0.0017
2023-05-12 2023-03-31 13F MPLX COM UNIT REP LTD 55336V100 14,607 0 0.00 503 5.01 0.0009
2023-02-10 2022-12-31 13F MPLX COM UNIT REP LTD 55336V100 14,607 2,268 18.38 480 29.46 0.0011
2022-11-14 2022-09-30 13F MPLX COM UNIT REP LTD 55336V100 12,339 -5,386 -30.39 370 -28.43 0.0008
2022-08-15 2022-06-30 13F MPLX COM UNIT REP LTD 55336V100 17,725 17,725 517 0.0011
2019-08-14 2019-06-30 13F MPLX COM UNIT REP LTD 55336V100 0 -135 -100.00 0 -100.00
2019-05-15 2019-03-31 13F MPLX COM UNIT REP LTD 55336V100 135 0 0.00 4 -20.00 0.0000
2019-02-13 2018-12-31 13F MPLX COM UNIT REP LTD 55336V100 135 0 0.00 5 0.00 0.0000
2018-11-08 2018-09-30 13F MPLX COM UNIT REP LTD 55336V100 135 -24 -15.09 5 -16.67 0.0000
2018-08-03 2018-06-30 13F MPLX COM UNIT REP LTD 55336V100 159 -654 -80.44 6 -76.92 0.0000
2018-05-11 2018-03-31 13F MPLX COM UNIT REP LTD 55336V100 813 376 86.04 26 62.50 0.0001
2018-02-08 2017-12-31 13F MPLX COM UNIT REP LTD 55336V100 437 -90 -17.08 16 -15.79 0.0001
2017-11-06 2017-09-30 13F MPLX COM UNIT REP LTD 55336V100 527 90 20.59 19 35.71 0.0001
2017-07-31 2017-06-30 13F MPLX COM UNIT REP LTD 55336V100 437 0 0.00 14 -12.50 0.0001
2017-05-05 2017-03-31 13F MPLX COM UNIT REP LTD 55336V100 437 0 0.00 16 0.00 0.0001
2017-02-02 2016-12-31 13F MPLX COM UNIT REP LTD 55336V100 437 0 0.00 16 14.29 0.0001
2016-11-04 2016-09-30 13F MPLX COM UNIT REP LTD 55336V100 437 218 99.54 14 100.00 0.0001
2016-08-11 2016-06-30 13F MPLX COM UNIT REP LTD 55336V100 219 -107 -32.82 7 -30.00 0.0000
2016-05-10 2016-03-31 13F/A-1 MPLX COM UNIT REP LTD 55336V100 326 107 48.86 10 11.11 0.0001
2016-02-03 2015-12-31 13F MPLX COM UNIT REP LTD 55336V100 219 219 9 0.0001
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.