Gallagher Thomas P. sold $2.2M of MIAX (indirect holdings)
Gallagher Thomas P. (Chairman & CEO) sold 48,334 indirectly-held shares of MIAMI INTERNATIONAL HOLDINGS, INC. (MIAX) at $45.69 ($2.21M total) on 2026-08-04 under a Rule 10b5-1 trading plan.
How this was made
The 30-second read
Why it matters
The newest fact is the specific open-market sale size, price, and timing by the CEO, plus confirmation it was executed under a pre-arranged 10b5-1 plan.
Market read
Traders may monitor insider activity for sentiment, but this disclosure alone does not provide a new fundamental catalyst.
What to watch
The article does not state whether other insiders sold/bought around the same time, nor does it provide total insider ownership changes beyond the post-transaction share count.
Background
The article is an SEC Form 4 insider transaction disclosure for Miami International Holdings, Inc. (MIAX).
Ticker impact
MIAX filed an SEC Form 4 showing CEO Thomas P. Gallagher sold 48,334 shares at $45.6900 on an open-market S trade under a 10b5-1 plan.
Low likelihood of a sustained price move; any reaction is likely limited to short-term sentiment around insider selling.
The filing is a routine Form 4 transaction with a pre-arranged 10b5-1 plan, and the article provides no new operational, financial, or regulatory catalyst for MIAX.
Market effects
Minimal. Insider sale disclosures typically do not reset sector expectations without accompanying company-specific fundamentals.
Minimal.
Minimal.
Counterpoint
Because the sale is explicitly under a pre-arranged 10b5-1 plan, it may reflect scheduled liquidity rather than bearish information.
Key entities
- issuerMIAX
Miami International Holdings, Inc., the company whose insider transaction was disclosed.
- insiderGallagher Thomas P.
Chairman and CEO who sold shares via an open-market transaction under a 10b5-1 plan.
