Private company
Who owns Matterhorn (MXP Parent, LLC)
One company in the researched set discloses a stake in Matterhorn (MXP Parent, LLC), worth $272m between them. Matterhorn (MXP Parent, LLC) is private, so no 13F reports it: a 13F covers exchange listed positions only. These figures exist because each holder disclosed the stake in its own filings.
Matterhorn (MXP Parent, LLC) - Profile
- Type
- joint venture
- Based in
- United States
- Founded
- 2022
Matterhorn, held through MXP Parent LLC, is the joint venture that owns the Matterhorn Express Pipeline, a 510 mile intrastate natural gas line in Texas built in 36 inch and 42 inch diameters. It carries up to about 2.5 billion cubic feet a day from the Permian Basin in West Texas across more than seventeen counties to the Katy area west of Houston, where the gas reaches Gulf Coast industrial demand and LNG export terminals. The line entered service in November 2024 and is operated by WhiteWater Midstream, which holds the largest stake alongside ONEOK, MPLX and Enbridge. The venture also owns 70 percent of the Eiger Express Pipeline, a second roughly 450 mile, 42 inch Permian to Katy line announced in 2025 with similar capacity and reserved capacity for the Corpus Christi market.
Source
Matterhorn (MXP Parent, LLC) files nothing with the SEC, so none of this comes from a filer record. The description was written for this site in August 2026 from Matterhorn Express Pipeline Project (Offshore Technology), ONEOK announces Permian-to-Gulf Coast region joint venture natural gas pipeline (PR Newswire) and Enbridge's Permian natural gas pipeline push continues. The ownership figures below come from the holders' filings instead, and are sourced row by row.
The disclosed stakes
One row per position. Where a holder reports the same company in two share classes, both rows are shown rather than summed, because the class is part of a position's identity.
Where each figure comes from
A private stake has no ownership form behind it, so the source is always the holder's own filing or disclosure. Anything modelled says so, with the arithmetic.
- ONEOK, Inc., as of 31 Dec 2025. Equity-method LLC interest, not denominated in shares, so shares is null. FY2025 10-K Note N investments table: 'Matterhorn 15% $272 $248' (2025 and 2024 carrying value in millions). Footnote (b): as of December 31, 2025, the 15% interest represents ONEOK's own ownership interest in Matterhorn acquired via the EnLink Acquisition (closed January 31, 2025); as of December 31, 2024, the same 15% represented EnLink's (then a separate company's) ownership interest. WhiteWater Midstream, LLC is the operator. Q2 2026 10-Q confirms the 15% owned joint venture with equity in net earnings of $14 million (Q2 2026) and $22 million (six months), no restated balance given. source
What this page is not
It is not a complete register. It lists the holders who happen to be inside the researched set and disclosed the stake themselves. A private company can have many other shareholders, and nothing here rules them out: venture investors, founders and employees usually appear in no public filing at all. Percentages are of Matterhorn (MXP Parent, LLC) where a holder stated one, and are missing where no holder did.