Form 4 for MIAX MIAMI INTERNATIONAL HOLDINGS, INC.
Accepted 2025-08-19 00:00:00 ET · period of report 2025-08-15 · accession 0001628280-25-040785 · SEC index · Original document
Summary rows
Aggregated the way they appear in lists: one row per insider, transaction code and security table.
| X | Filed | Traded | Ticker | Insider | Title | Type | Price | Qty | Owned | ΔOwn | Value |
|---|---|---|---|---|---|---|---|---|---|---|---|
| DMI | 2025-08-19 | 2025-08-15 | MIAX | Gallagher Thomas P. | COB, CEO, Dir | C - Cnv Deriv | — | +135.9K | 2.04M | +7% | — |
| D | 2025-08-19 | 2025-08-15 | MIAX | Gallagher Thomas P. | COB, CEO, Dir | C - Cnv Deriv | — | +574.0K | 586.0K | +4,783% | — |
| DMI | 2025-08-19 | 2025-08-15 | MIAX | Gallagher Thomas P. | COB, CEO, Dir | M - OptEx | $0.00 | 0 | 0 | New | $0 |
| DM | 2025-08-19 | 2025-08-15 | MIAX | Gallagher Thomas P. | COB, CEO, Dir | M - OptEx | $0.00 | 0 | 25.0K | New | $0 |
| DMI | 2025-08-19 | 2025-08-15 | MIAX | Gallagher Thomas P. | COB, CEO, Dir | C - Cnv Deriv | $0.00 | -135.9K | 0 | -100% | $0 |
| D | 2025-08-19 | 2025-08-15 | MIAX | Gallagher Thomas P. | COB, CEO, Dir | C - Cnv Deriv | $0.00 | -574.0K | 0 | -100% | $0 |
Purchase Sale Sale after option exercise All abbreviations
Every reported transaction
| # | Table | Security | Date | Code | A/D | Shares | Price | Owned after | Own | Exercise / expiry | Underlying | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Common | Common Stock | 2025-08-15 | C | A | 500 | — | 2,040,494 | I By Gallagher Investments, LLC | — | — | (F1) Represents 500 shares of Series B Preferred Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's initial public offering ("IPO") and which have no expiration date. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC |
| 2 | Common | Common Stock | 2025-08-15 | C | A | 135,395 | — | 2,040,494 | I | — | — | (F5) Represents 135,395 shares of Nonvoting Common Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's IPO and which have no expiration date. |
| 3 | Common | Common Stock | 2025-08-15 | C | A | 573,963 | — | 585,963 | D By Gallagher Investments, LLC | — | — | (F3) Represents 573,963 shares of Nonvoting Common Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's IPO and which have no expiration date. (F4) Includes 12,000 shares of common stock jointly with his spouse with right of survival (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC |
| 4 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | A | 241,667 | $0.00 | 241,667 | I | $12.00 · — to 2029-07-30 | 241,667 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 5 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | D | 16,666 | $0.00 | 0 | D By Gallagher Investments, LLC | $12.00 · — to 2028-05-28 | 16,666 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 6 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | A | 283,334 | $0.00 | 283,334 | I | $12.00 · — to 2028-05-28 | 283,334 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 7 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | D | 283,334 | $0.00 | 0 | I | $12.00 · — to 2028-05-28 | 283,334 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 8 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | A | 375,000 | $0.00 | 375,000 | I | $16.14 · — to 2031-09-09 | 375,000 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 9 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | D | 375,000 | $0.00 | 0 | I | $16.14 · — to 2031-09-09 | 375,000 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 10 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | A | 286,860 | $0.00 | 286,860 | I | $15.22 · — to 2031-01-27 | 286,860 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 11 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | D | 286,860 | $0.00 | 0 | I | $15.22 · — to 2031-01-27 | 286,860 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 12 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | A | 350,001 | $0.00 | 350,001 | I | $12.00 · — to 2026-08-02 | 350,001 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |
| 13 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | D | 350,001 | $0.00 | 0 | I By Gallagher Investments, LLC | $12.00 · — to 2026-08-02 | 350,001 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 14 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | A | 13,140 | $0.00 | 13,140 | D By Gallagher Investments, LLC | $15.22 · — to 2031-01-27 | 13,140 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 15 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | D | 13,140 | $0.00 | 0 | D By Gallagher Investments, LLC | $15.22 · — to 2031-01-27 | 13,140 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 16 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | A | 8,333 | $0.00 | 8,333 | D By Gallagher Investments, LLC | $12.00 · — to 2029-07-30 | 8,333 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 17 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | D | 8,333 | $0.00 | 0 | D By Gallagher Investments, LLC | $12.00 · — to 2029-07-30 | 8,333 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 18 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | A | 16,666 | $0.00 | 16,666 | D By Gallagher Investments, LLC | $12.00 · — to 2028-05-28 | 16,666 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 19 | Derivative | Series B Preferred Stock | 2025-08-15 | C | D | 500 | $0.00 | 0 | I By Gallagher Investments, LLC | — · — to — | 500 Common Stock | (F1) Represents 500 shares of Series B Preferred Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's initial public offering ("IPO") and which have no expiration date. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC |
| 20 | Derivative | Nonvoting Common Stock | 2025-08-15 | C | D | 573,963 | $0.00 | 0 | D By Gallagher Investments, LLC | — · — to — | 573,963 Common Stock | (F3) Represents 573,963 shares of Nonvoting Common Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's IPO and which have no expiration date. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC |
| 21 | Derivative | Nonvoting Common Stock | 2025-08-15 | C | D | 135,395 | $0.00 | 0 | I By Gallagher Investments, LLC | — · — to — | 135,395 Common Stock | (F5) Represents 135,395 shares of Nonvoting Common Stock that have been converted into shares of Common Stock on a one-for-one basis upon the closing of the Company's IPO and which have no expiration date. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC |
| 22 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | D | 24,999 | $0.00 | 0 | D By Gallagher Investments, LLC | $12.00 · — to 2026-08-02 | 24,999 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 23 | Derivative | Incentive Stock Option (Right to Buy) | 2025-08-15 | M | A | 24,999 | $0.00 | 24,999 | D By Gallagher Investments, LLC | $12.00 · — to 2026-08-02 | 24,999 Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F2) Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC (F7) The options are fully vested. |
| 24 | Derivative | Nonqualified Stock Option (Right to Buy) | 2025-08-15 | M | D | 241,667 | $0.00 | 0 | I | $12.00 · — to 2029-07-30 | 241,667 Nonvoting Common Stock | (F6) The options were granted initially as the right to buy Nonvoting Common Stock. On the closing date of the IPO, these converted to the right to buy Common Stock instead of Nonvoting Common Stock, for the same price and under the same conditions. (F7) The options are fully vested. |