Great Mountain Partners LLC portfolio

Every position on this page is a snapshot of 2026-03-31. It was already 43 days old on 2026-05-13, the day it first became public. Today it is 134 days old.

That lag is the law, not a service level — Rule 13f-1 gives managers 45 days after quarter end to file, and no product can shorten it. A fund can have sold every share below before you read this sentence. Treat it as a record of what happened, never as a position you can follow.

This page was built from one document: the 2026-03-31 Form 13F info table filed by Great Mountain Partners LLC (CIK 1815467, accession 0001815467-26-000001). Every other 13F site is reading the same file.

One quirk worth naming: this manager still reports position values in thousands, although Form 13F has required whole dollars since 2023. We detect that by comparing this filing’s implied price per share against what every other manager holding the same securities reported for them this quarter — and multiply by 1,000. Figures on this page are therefore 1,000x the numbers you will read in the document itself.

If anything here disagrees with it, the filing wins — and we would want to know. All 13F filings by this manager

A 13F is a long-only equity snapshot, and the holes in it are structural. Anyone selling you this data as "what the smart money is doing" is selling you one leg of a position:

• No short positions. None, ever. A fund shown here as bullish may be net short the same name through a book you cannot see.
• No cash, bonds, FX, commodities or non-US listings. A macro fund's entire thesis can be invisible.
• No intra-quarter round trips. Bought and sold inside the same quarter means it never appears at all.
• Options are notional, not ownership. We keep puts and calls in a separate bucket rather than adding their notional into a fund's book size, which is how a $2B fund gets reported as a $20B one.
• Confidential treatment. Managers can ask the SEC to withhold a position while they build it. Those holdings are legally absent from the filing, so a "new" position may be months old.