Private company
Who owns Midcontinent Grid Solutions, LLC (MGS)
One company in the researched set discloses a stake in Midcontinent Grid Solutions, LLC (MGS), none of it sized by anyone who discloses it. Midcontinent Grid Solutions, LLC (MGS) 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.
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.
- American Electric Power Company, Inc.. The FY2025 10-K glossary states MGS 'is 43.25% owned by AEP' directly. MGS was formed in 2025 by Transource Energy and a Berkshire Hathaway Energy affiliate to bid into MISO's 2024 Regional Transmission Expansion Plan; in January 2026 MISO selected MGS's proposed Wisconsin upgrades, estimated to cost approximately $1.2 billion, of which Transource Energy's (not AEP's own) estimated share of the investment is $600 million. No separate carrying value for AEP's look-through interest in MGS is disclosed in either the 10-K or the Q2 FY2026 10-Q. 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 Midcontinent Grid Solutions, LLC (MGS) where a holder stated one, and are missing where no holder did.