Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
636 institutional managers reported holding MPLX for the quarter ended Mar 31, 2026. Together they hold about 20% of shares outstanding; the top 10 hold 12%. 77 opened new positions; 64 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Alps Advisors INC | 27.07M | 2.67% | $1.55B | added +6201.9% | 2015 Q2 |
| Invesco | 18.27M | 1.80% | $1.04B | unchanged | 2014 Q3 |
| Blackstone | 15.35M | 1.51% | $876.4M | trimmed -2.3% | 2020 Q1 |
| Tortoise Capital Advisors, L.l.c. | 13.26M | 1.31% | $757.0M | unchanged | ≤2013 |
| Goldman Sachs | 12.51M | 1.23% | $714.1M | unchanged | ≤2013 |
| Mirae Asset Global Etfs Holdings LTD. | 7.32M | 0.72% | $417.9M | added +5.9% | 2018 Q3 |
| Kayne Anderson Capital Advisors LP (focused) | 6.83M | 0.67% | $389.7M | trimmed -5.5% | 2014 Q4 |
| UBS | 5.23M | 0.52% | $298.8M | trimmed -1.3% | ≤2013 |
| Chickasaw Capital Management LLC | 5.22M | 0.52% | $298.2M | trimmed -3.8% | ≤2013 |
| Energy Income Partners, LLC | 5.16M | 0.51% | $294.4M | trimmed -2.7% | 2021 Q4 |
| Morgan Stanley | 4.96M | 0.49% | $283.4M | trimmed -13.9% | ≤2013 |
| Bank OF Montreal /CAN/ | 4.03M | 0.40% | $229.9M | added +71257.7% | 2024 Q1 |
| FMR (Fidelity) | 3.36M | 0.33% | $191.9M | added +101.4% | 2013 Q4 |
| Brave Warrior Advisors, LLC (focused) | 3.25M | 0.32% | $185.7M | trimmed -27.3% | 2023 Q2 |
| Cibc Bancorp USA INC. | 2.64M | 0.26% | $150.8M | trimmed -3% | 2014 Q1 |
| Bank OF America CORP /DE/ | 2.57M | 0.25% | $146.9M | trimmed -69.8% | ≤2013 |
| Clearbridge Investments, LLC | 2.34M | 0.23% | $133.8M | unchanged | 2015 Q4 |
| Miller Howard Investments INC /NY | 2.24M | 0.22% | $127.9M | trimmed -3.3% | 2014 Q4 |
| Westwood Holdings Group INC | 2.24M | 0.22% | $127.7M | added +5211.1% | 2022 Q4 |
| Brookfield CORP /ON/ | 2.17M | 0.21% | $124.1M | trimmed -26.6% | 2015 Q4 |
| Fractal Investments LLC | 2.05M | 0.20% | $117.1M | unchanged | 2021 Q4 |
| Cushing Asset Management, LP dba NXG Investment Management | 1.86M | 0.18% | $106.1M | trimmed -1.3% | ≤2013 |
| Eagle Global Advisors LLC | 1.81M | 0.18% | $103.1M | trimmed -4.2% | 2015 Q4 |
| ING Groep NV | 1.77M | 0.17% | $100.9M | trimmed -39.1% | 2018 Q4 |
| Duff & Phelps Investment Management CO | 1.67M | 0.16% | $95.3M | trimmed -8.9% | 2015 Q4 |
| AlphaCore Capital LLC | 1.62M | 0.16% | $92.2M | added +0.6% | 2023 Q2 |
| Stifel Financial CORP | 1.33M | 0.13% | $76.0M | unchanged | 2015 Q4 |
| BNP Paribas Financial Markets | 1.29M | 0.13% | $73.7M | added +16.7% | 2014 Q4 |
| Mariner, LLC | 1.15M | 0.11% | $65.8M | unchanged | 2015 Q4 |
| Royal Bank OF Canada | 1.15M | 0.11% | $65.8M | added +45.5% | 2013 Q3 |
| Epoch Investment Partners, INC. | 1.13M | 0.11% | $64.4M | trimmed -2.5% | 2022 Q2 |
| Neuberger Berman Group LLC | 1.10M | 0.11% | $62.8M | trimmed -2.2% | 2015 Q4 |
| Infrastructure Capital Advisors, LLC | 1.07M | 0.10% | $61.0M | added +2.9% | 2016 Q4 |
| Progeny 3, INC. (focused) | 1.02M | 0.10% | $58.0M | trimmed -4.1% | 2021 Q3 |
| Raymond James Financial INC | 977.9k | 0.10% | $55.8M | added +2.3% | 2015 Q4 |
| Victory Capital Management INC | 971.5k | 0.10% | $55.5M | added +1401% | 2025 Q2 |
| Cohen & Steers | 929.8k | 0.09% | $53.1M | added +5.6% | ≤2013 |
| Barclays PLC | 887.2k | 0.09% | $50.7M | trimmed -3.1% | 2013 Q3 |
| Deutsche Bank AG\ | 853.8k | 0.08% | $48.7M | unchanged | 2013 Q3 |
| Allianz Asset Management GmbH | 829.1k | 0.08% | $47.3M | unchanged | 2020 Q4 |
| Wells Fargo & COMPANY/MN | 805.2k | 0.08% | $46.0M | added +7.6% | ≤2013 |
| Americana Partners, LLC | 765.5k | 0.07% | $43.7M | added +0.7% | 2019 Q4 |
| Reaves W H & CO INC | 670.5k | 0.07% | $38.3M | unchanged | 2024 Q4 |
| Longfellow Investment Management CO LLC | 579.5k | 0.06% | $33.1M | trimmed -24.4% | 2020 Q4 |
| U.s. Capital Wealth Advisors, LLC | 577.6k | 0.06% | $33.0M | unchanged | 2021 Q3 |
| Jennison Associates LLC | 545.1k | 0.05% | $31.1M | trimmed -18.7% | 2016 Q2 |
| Appaloosa (focused) | 502.5k | 0.05% | $28.7M | trimmed -19.9% | 2020 Q4 |
| Chicago Partners Investment Group LLC | 486.7k | 0.05% | $27.8M | added +1.5% | 2015 Q3 |
| LPL Financial LLC | 476.7k | 0.05% | $27.2M | unchanged | 2015 Q4 |
| Oxbow Advisors, LLC | 434.0k | 0.04% | $24.8M | added +7.1% | 2020 Q4 |
Largest 50 of 636 shown; the full ranked, searchable register is at boothcheck.com/holders/MPLX. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.