Miami International Holdings, Inc.
MIAX- Exchange
- NYSE
- Industry
- Security Brokers, Dealers & Flotation Companies
- SEC CIK
- 0001438472
In the last 90 days, Miami International Holdings, Inc. insiders filed 0 open-market purchases and 27 sales; 206 institutions reported holding it in 13F filings for Q2 2026, worth $2.68B in total; no superinvestor holds it.
Holders of 5% or more of MIAX
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Miami International Holdings, Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Horizon Kinetics Asset Management LLC | 13D/A | 11.70%9.50M shares | +1.00 ppfrom 10.70% | Aug 21, 20252 filings | Nov 26, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
4 Schedule 13D and 13G filings on Miami International Holdings, Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Nov 26, 20251:35 PM ET | Horizon Kinetics Asset Management LLC | 13D/A | 11.70%9.50M shares | +1.00 ppfrom 10.70% | Nov 24, 2025 | SEC |
| Aug 28, 20254:30 PM ET | Gallagher Thomas P.and 1 other | 13D/A | 4.90%4.04M shares | −0.20 ppfrom 5.10%Below 5% | Aug 26, 2025 | SEC |
| Aug 21, 20254:24 PM ET | Gallagher Thomas P.and 1 other | 13D | 5.10%4.23M shares | New | Aug 14, 2025 | SEC |
| Aug 21, 20252:46 PM ET | Horizon Kinetics Asset Management LLC | 13D | 10.70%8.68M shares | New | Aug 14, 2025 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Miami International Holdings, Inc. shares.
No Form 144 notices for Miami International Holdings, Inc. are on file.