MIAMI International (MIAX) CEO sells 70K shares after option exercise
Filing Impact
Filing Sentiment
Form Type
4
Rhea-AI Filing Summary
MIAMI INTERNATIONAL HOLDINGS, INC. Chairman & CEO Thomas P. Gallagher, through Gallagher Investments, LLC, completed a paired option exercise and share sale in MIAX common stock. On July 6–7, 2026, Gallagher Investments exercised nonqualified stock options for a total of 70,000 shares at an exercise price of $12.00 per share and sold the same 70,000 shares in open-market transactions at weighted average prices of $42.09 and $42.27 per share.
All reported transactions were executed under a previously established Rule 10b5-1 Plan adopted on December 29, 2025, indicating they were pre-scheduled. Following these transactions, Gallagher Investments holds 1,723,275 shares of MIAX common stock indirectly for Gallagher, who maintains voting and dispositive control.
Positive
- None.
Negative
- None.
Insider Trade Summary 10b5-1
Net Seller: 70,000 shares ($2,951,381)
Net Sell
6 txns
Insider
Gallagher Thomas P.
Role
Chairman & CEO
Sold
70,000 shs ($2.95M)
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Exercise | Nonqualified Stock Option (Right to Buy) | 28,228 | $0.00 | -- |
| Exercise | Common Stock | 28,228 | $12.00 | $339K |
| Sale | Common Stock | 28,228 | $42.27 | $1.19M |
| Exercise | Nonqualified Stock Option (Right to Buy) | 41,772 | $0.00 | -- |
| Exercise | Common Stock | 41,772 | $12.00 | $501K |
| Sale | Common Stock | 41,772 | $42.09 | $1.76M |
Holdings After Transaction:
Nonqualified Stock Option (Right to Buy) — 70,000 shares (Indirect, By Gallagher Investments, LLC);
Common Stock — 1,751,503 shares (Indirect, By Gallagher Investments, LLC)
Footnotes (1)
- This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $42.32. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $42.50. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. The options are fully vested.
Key Figures
Shares sold: 70,000 shares
Sale prices July 6: $42.09 per share
Sale prices July 7: $42.27 per share
+3 more
6 metrics
Shares sold
70,000 shares
Open-market sales of MIAX common stock
Sale prices July 6
$42.09 per share
Weighted average sale price on July 6, 2026
Sale prices July 7
$42.27 per share
Weighted average sale price on July 7, 2026
Option exercise price
$12.00 per share
Nonqualified stock option exercise price
Shares acquired via exercise
70,000 shares
Common shares from option exercises
Post-transaction holdings
1,723,275 shares
Indirect MIAX holdings via Gallagher Investments, LLC
Key Terms
Rule 10b5-1 Plan, Nonqualified Stock Option (Right to Buy), beneficial ownership, open-market sale, +1 more
5 terms
Rule 10b5-1 Plan regulatory
"This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025."
A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.
Nonqualified Stock Option (Right to Buy) financial
"security_title: "Nonqualified Stock Option (Right to Buy)" with an exercise price of $12.0000."
beneficial ownership financial
"Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC."
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
open-market sale financial
"transaction_action: "open-market sale" for MIAX common stock transactions coded S."
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
derivative exercise/conversion financial
"transaction_action: "derivative exercise/conversion" for option exercises coded M."
FAQ
What did MIAX Chairman & CEO Thomas Gallagher do in this Form 4 filing?
Thomas Gallagher’s affiliated entity exercised options for 70,000 MIAX shares at $12.00 and sold the same 70,000 shares around $42. The transactions reflect an exercise-and-sell pattern rather than a simple open-market purchase or sale.
What option exercise price is disclosed for Thomas Gallagher’s MIAX options?
The filing shows Gallagher’s affiliated entity exercised nonqualified stock options with a conversion or exercise price of $12.00 per share. Those options converted into 70,000 MIAX common shares, which were then sold in the open market at prices around $42 per share.
How are Thomas Gallagher’s MIAX holdings structured according to the Form 4 footnotes?
The shares are held indirectly through Gallagher Investments, LLC, which is listed as the owner for the transactions. The footnotes state Gallagher maintains beneficial ownership with both voting and dispositive control over this LLC’s MIAX common stock holdings.