MPLX LP - Limited Partnership
US ˙ NYSE ˙ US55336V1008

SecurityMPLX / MPLX LP - Limited Partnership
InstitutionCohen & Steers, Inc.
Latest Disclosed Ownership929,751 shares
Latest Disclosed Value $ 53,061
Cohen & Steers, Inc. reports 5.58% increase in ownership of MPLX / MPLX LP - Limited Partnership

On May 15, 2026 - Cohen & Steers, Inc. filed a 13F-HR form disclosing ownership of 929,751 shares of MPLX LP - Limited Partnership (US:MPLX) valued at $53,060,890 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 880,593 shares of MPLX LP - Limited Partnership. This represents a change in shares of 5.58% during the quarter. The current value of the position is $52,512,336 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)
2026-05-15 2026-03-31 13F MPLX COM 55336V100 929,751 49,158 5.58 53 15.22 0.0922
2026-02-13 2025-12-31 13F MPLX COM 55336V100 880,593 189,306 27.38 47 35.29 0.0850
2025-11-14 2025-09-30 13F MPLX COM 55336V100 691,287 0 0.00 35 -2.86 0.0623
2025-08-14 2025-06-30 13F MPLX COM 55336V100 691,287 34,320 5.22 36 0.00 0.0653
2025-05-15 2025-03-31 13F MPLX COM 55336V100 656,967 -571 -0.09 35 12.90 0.0650
2025-02-13 2024-12-31 13F MPLX COM 55336V100 657,538 23,025 3.63 31 10.71 0.0596
2024-11-14 2024-09-30 13F MPLX COM 55336V100 634,513 118,983 23.08 28 33.33 0.0502
2024-08-13 2024-06-30 13F MPLX COM 55336V100 515,530 0 0.00 22 0.00 0.0460
2024-05-15 2024-03-31 13F MPLX COM 55336V100 515,530 571 0.11 21 16.67 0.0448
2024-02-14 2023-12-31 13F MPLX COM 55336V100 514,959 0 0.00 19 0.00 0.0383
2023-11-14 2023-09-30 13F MPLX COM 55336V100 514,959 -68,721 -11.77 18 -5.26 0.0421
2023-08-14 2023-06-30 13F MPLX COM 55336V100 583,680 -125,548 -17.70 20 -20.83 0.0417
2023-05-15 2023-03-31 13F MPLX COM 55336V100 709,228 -6,373 -0.89 24 -99.90 0.0528
2023-02-14 2022-12-31 13F MPLX COM 55336V100 715,601 -9,045 -1.25 23,500 8.06 0.0519
2022-11-14 2022-09-30 13F MPLX COM 55336V100 724,646 -9,469 -1.29 21,747 1.63 0.0487
2022-08-15 2022-06-30 13F MPLX COM 55336V100 734,115 -1 -0.00 21,399 -12.15 0.0420
2022-05-16 2022-03-31 13F MPLX COM 55336V100 734,116 28,105 3.98 24,358 16.60 0.0408
2022-02-14 2021-12-31 13F MPLX COM 55336V100 706,011 14,612 2.11 20,891 6.13 0.0339
2021-11-15 2021-09-30 13F MPLX COM 55336V100 691,399 -543,241 -44.00 19,684 -46.16 0.0367
2021-08-16 2021-06-30 13F MPLX COM 55336V100 1,234,640 11,852 0.97 36,558 16.65 0.0694
2021-05-17 2021-03-31 13F MPLX COM 55336V100 1,222,788 -75,352 -5.80 31,340 11.51 0.0672
2021-02-16 2020-12-31 13F MPLX COM 55336V100 1,298,140 15,423 1.20 28,105 39.20 0.0676
2020-11-16 2020-09-30 13F MPLX COM 55336V100 1,282,717 73,056 6.04 20,190 -3.41 0.0538
2020-08-14 2020-06-30 13F MPLX COM 55336V100 1,209,661 31,302 2.66 20,903 52.65 0.0583
2020-05-15 2020-03-31 13F MPLX COM 55336V100 1,178,359 -908,592 -43.54 13,693 -74.23 0.0442
2020-02-14 2019-12-31 13F MPLX COM 55336V100 2,086,951 67,171 3.33 53,134 -6.08 0.1322
2019-11-14 2019-09-30 13F MPLX COM 55336V100 2,019,780 586,584 40.93 56,574 22.63 0.1418
2019-08-14 2019-06-30 13F MPLX COM 55336V100 1,433,196 61,626 4.49 46,135 2.27 0.1280
2019-05-15 2019-03-31 13F MPLX COM 55336V100 1,371,570 -770,889 -35.98 45,111 -30.51 0.1251
2019-02-14 2018-12-31 13F MPLX COM 55336V100 2,142,459 -171,394 -7.41 64,917 -19.10 0.2065
2018-11-16 2018-09-30 13F/A-1 MPLX COM 55336V100 2,313,853 -430,126 -15.68 80,244 -14.34 0.2333
2018-11-14 2018-09-30 13F MPLX COM 55336V100 2,313,853 -430,126 80,244
2018-08-14 2018-06-30 13F MPLX COM 55336V100 2,743,979 252,980 10.16 93,679 13.82 0.2683
2018-05-14 2018-03-31 13F MPLX COM 55336V100 2,490,999 65,213 2.69 82,303 -4.35 0.2517
2018-02-14 2017-12-31 13F MPLX COM 55336V100 2,425,786 1,544,638 175.30 86,043 178.92 0.2378
2017-11-14 2017-09-30 13F MPLX COM 55336V100 881,148 116,515 15.24 30,849 20.79 0.0842
2017-08-14 2017-06-30 13F MPLX COM 55336V100 764,633 138,798 22.18 25,539 13.10 0.0677
2017-05-15 2017-03-31 13F MPLX COM 55336V100 625,835 -104,414 -14.30 22,580 -10.68 0.0604
2017-02-14 2016-12-31 13F MPLX COM 55336V100 730,249 -13,454 -1.81 25,281 0.39 0.0698
2016-11-14 2016-09-30 13F MPLX COM 55336V100 743,703 -66,281 -8.18 25,182 -7.56 0.0646
2016-08-22 2016-06-30 13F/A-2 MPLX COM 55336V100 809,984 -735,028 -47.57 27,240 -40.62 0.0705
2016-08-18 2016-06-30 13F/A-1 MPLX COM 55336V100 254,406 -555,578 5,177 0.0136
2016-08-15 2016-06-30 13F MPLX COM 55336V100 809,984 27,240
2016-05-16 2016-03-31 13F MPLX COM 55336V100 1,545,012 -118,721 -7.14 45,871 -29.90 0.1270
2016-02-16 2015-12-31 13F MPLX COM 55336V100 1,663,733 1,452,622 688.08 65,435 711.14 0.1881
2015-11-16 2015-09-30 13F MPLX COM 55336V100 211,111 0 0.00 8,067 -46.47 0.0244
2015-08-14 2015-06-30 13F MPLX COM 55336V100 211,111 0 0.00 15,069 -2.57 0.0457
2015-05-15 2015-03-31 13F MPLX COM 55336V100 211,111 211,111 0.00 15,466 0.0418
2015-02-17 2014-12-31 13F MPLX COM 55336V100 0 -382,802 -100.00 0 -100.00
2014-11-14 2014-09-30 13F MPLX COM 55336V100 382,802 -72,431 -15.91 22,562 -23.16 0.0683
2014-08-14 2014-06-30 13F MPLX COM 55336V100 455,233 -161,724 -26.21 29,363 -2.85 0.0841
2014-05-15 2014-03-31 13F MPLX COM 55336V100 616,957 17,274 2.88 30,225 13.16 0.0914
2014-02-14 2013-12-31 13F MPLX COM 55336V100 599,683 -190,227 -24.08 26,710 -7.21 0.0873
2013-11-14 2013-09-30 13F MPLX COM 55336V100 789,910 388,520 96.79 28,784 94.82 0.0929
2013-08-14 2013-06-30 13F MPLX COM 55336V100 401,390 401,390 14,775 0.0459
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.