Reported relationships
Latest disclosed role at each company.
| Company | Last reported as | Report date | Published |
|---|---|---|---|
| MIAMI INTERNATIONAL HOLDINGS, INC.MIAX · Entity 4026 | Director · Chairman & CEO | September 03, 2026 | September 04, 2026 |
Disclosed balances
About these balances
Latest available filing per company, not a reconstructed current portfolio. Matching sequences show the last reported balance with all source rows expandable; grouping alone does not establish account ownership. Do not add unresolved positions together. Filings may omit unchanged positions, and amendments may correct only part of an older disclosure. Jointly reported shares are not necessarily this owner's personal holdings.
MIAMI INTERNATIONAL HOLDINGS, INC.
Report date September 03, 2026 · Filed September 04, 2026
| Security / award | Ownership account | Disclosed shares / units | Disclosure context |
|---|---|---|---|
| Common StockSEC Table I · non-derivative | IndirectBy Gallagher Investments, LLC | 1,423,275 |
Last balance in matching sequence
After 2026-09-03 transaction · row 2
Source-order balances reconcile. Account continuity and personal attribution are not independently verified.
2 source rowsRow 1 · 2026-09-03 · Exercise / conversion · Acquired 47,000 · Balance 1,470,275 F1: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Row 2 · 2026-09-03 · Sale · Disposed 47,000 · Balance 1,423,275 F1: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3: This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $42.68. 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. F2: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. |
| Common StockSEC Table I · non-derivative | Direct | 786,542 |
Ending reported balance
After 2026-09-03 transaction · row 6
4 source rows · reconciled sequenceRow 3 · 2026-09-03 · Exercise / conversion · Acquired 16,666 · Balance 760,605 Row 4 · 2026-09-03 · Exercise / conversion · Acquired 8,333 · Balance 768,938 Row 5 · 2026-09-03 · Exercise / conversion · Acquired 13,140 · Balance 782,078 Row 6 · 2026-09-03 · Exercise / conversion · Acquired 4,464 · Balance 786,542 |
| Nonqualified Stock Option (Right to Buy)SEC Table II · derivative / convertible security · Conversion / exercise price $12.00 · Expires 2028-05-28 | IndirectBy Gallagher Investments, LLC | 188,000 |
Reported balance
After 2026-09-03 transaction · row 7
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 7 · 2026-09-03 · Exercise / conversion · Disposed 47,000 · Balance 188,000 F1: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4: The options are fully vested. F2: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. |
| Incentive Stock Option (Right to Buy)SEC Table II · derivative / convertible security · Conversion / exercise price $12.00 · Expires 2028-05-28 | Direct | 0 |
Reported balance
After 2026-09-03 transaction · row 8
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 8 · 2026-09-03 · Exercise / conversion · Disposed 16,666 · Balance 0 F4: The options are fully vested. |
| Incentive Stock Option (Right to Buy)SEC Table II · derivative / convertible security · Conversion / exercise price $12.00 · Expires 2029-07-30 | Direct | 0 |
Reported balance
After 2026-09-03 transaction · row 9
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 9 · 2026-09-03 · Exercise / conversion · Disposed 8,333 · Balance 0 F4: The options are fully vested. |
| Incentive Stock Option (Right to Buy)SEC Table II · derivative / convertible security · Conversion / exercise price $15.22 · Expires 2031-01-27 | Direct | 0 |
Reported balance
After 2026-09-03 transaction · row 10
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 10 · 2026-09-03 · Exercise / conversion · Disposed 13,140 · Balance 0 F4: The options are fully vested. |
| Incentive Stock Option (Right to Buy)SEC Table II · derivative / convertible security · Conversion / exercise price $22.40 · Expires 2035-06-15 | Direct | 8,928 |
Reported balance
After 2026-09-03 transaction · row 11
Instrument identity requires review; Table II rows are not merged.
1 source rowRow 11 · 2026-09-03 · Exercise / conversion · Disposed 4,464 · Balance 8,928 F5: 4,464 of the shares subject to this incentive stock option are vested. 4,464 shares subject to this incentive stock option will vest on June 16, 2027 and the remaining 4,464 shares subject to this incentive stock option will vest on June 16, 2028, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date. |
Filing footnotes · ownership attribution and instrument terms
F1: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025.
F2: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC.
F3: This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $42.68. 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.
F4: The options are fully vested.
F5: 4,464 of the shares subject to this incentive stock option are vested. 4,464 shares subject to this incentive stock option will vest on June 16, 2027 and the remaining 4,464 shares subject to this incentive stock option will vest on June 16, 2028, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date.
Transaction history
JSON APIPurchases/sales include open-market and private transactions. Plan disclosure applies to the filing; individual rows may differ. “Not disclosed” is not “unplanned.”
The cutoff filters transaction history only. Company summaries and owner relationships show the latest available disclosures. Parser corrections can improve historical records.
| Transaction date | Company | Activity / security | Shares / units | Reported price | Reported value | Details |
|---|---|---|---|---|---|---|
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionIncentive Stock Option (Right to Buy) · Derivative | 4,464 | $0.00 Strike: $22.40 | $0.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · derivative · entry 11 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 8,928 Underlying: Common Stock · 4,464 shares Expires 2035-06-15 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F5 · derivative.exercise_date: 4,464 of the shares subject to this incentive stock option are vested. 4,464 shares subject to this incentive stock option will vest on June 16, 2027 and the remaining 4,464 shares subject to this incentive stock option will vest on June 16, 2028, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionIncentive Stock Option (Right to Buy) · Derivative | 13,140 | $0.00 Strike: $15.22 | $0.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · derivative · entry 10 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 0 Underlying: Common Stock · 13,140 shares Expires 2031-01-27 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F4 · derivative.exercise_date: The options are fully vested. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionIncentive Stock Option (Right to Buy) · Derivative | 8,333 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · derivative · entry 9 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 0 Underlying: Common Stock · 8,333 shares Expires 2029-07-30 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F4 · derivative.exercise_date: The options are fully vested. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionIncentive Stock Option (Right to Buy) · Derivative | 16,666 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · derivative · entry 8 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 0 Underlying: Common Stock · 16,666 shares Expires 2028-05-28 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F4 · derivative.exercise_date: The options are fully vested. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 47,000 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · derivative · entry 7 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 188,000 Underlying: Common Stock · 47,000 shares Expires 2028-05-28 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 4,464 | $22.40 | $99,993.60 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · nonDerivative · entry 6 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 786,542 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 13,140 | $15.22 | $199,990.80 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · nonDerivative · entry 5 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 782,078 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 8,333 | $12.00 | $99,996.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · nonDerivative · entry 4 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 768,938 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 16,666 | $12.00 | $199,992.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · nonDerivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 760,605 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 47,000 | $42.43 | $1,994,210.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,423,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $42.68. 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| September 03, 2026 Filed Sep 4, 2026 20:35 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 47,000 | $12.00 | $564,000.00 |
DisclosureSEC source: 0002080477-26-000018 · wk-form4_1788554097.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,470,275 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| August 19, 2026 Filed Aug 20, 2026 20:12 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 149,700 | $41.13 | $6,157,161.00 |
DisclosureSEC source: 0002080477-26-000016 · wk-form4_1787256723.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,423,275 F3 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $38.85 to $42.56. 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| August 18, 2026 Filed Aug 20, 2026 20:12 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Tax withholdingCommon Stock | 150,300 | $42.41 | $6,374,223.00 |
DisclosureSEC source: 0002080477-26-000016 · wk-form4_1787256723.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,572,975 F1 · shares: Represents shares that have been surrendered to the Company to satisfy tax withholding and remittance obligations in connection with the net settlement of restricted stock awards and does not represent a sale by the reporting person. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| August 04, 2026 Filed Aug 6, 2026 20:05 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 48,334 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000014 · wk-form4_1786046744.xml · derivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 235,000 Underlying: Common Stock · 48,334 shares Expires 2028-05-28 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| August 04, 2026 Filed Aug 6, 2026 20:05 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 48,334 | $45.69 | $2,208,380.46 |
DisclosureSEC source: 0002080477-26-000014 · wk-form4_1786046744.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $45.09 to $46.78. 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| August 04, 2026 Filed Aug 6, 2026 20:05 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 48,334 | $12.00 | $580,008.00 |
DisclosureSEC source: 0002080477-26-000014 · wk-form4_1786046744.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,771,609 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 13, 2026 Filed Jul 14, 2026 20:04 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 70,000 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0001628280-26-048149 · wk-form4_1784059473.xml · derivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 0 Underlying: Common Stock · 70,000 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 13, 2026 Filed Jul 14, 2026 20:04 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 70,000 | $42.52 | $2,976,400.00 |
DisclosureSEC source: 0001628280-26-048149 · wk-form4_1784059473.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $43.49. 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 13, 2026 Filed Jul 14, 2026 20:04 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 70,000 | $12.00 | $840,000.00 |
DisclosureSEC source: 0001628280-26-048149 · wk-form4_1784059473.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,793,275 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 07, 2026 Filed Jul 7, 2026 21:03 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 28,228 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0001628280-26-047530 · wk-form4_1783458198.xml · derivative · entry 6 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 70,000 Underlying: Common Stock · 28,228 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F5 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 07, 2026 Filed Jul 7, 2026 21:03 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 28,228 | $42.27 | $1,193,197.56 |
DisclosureSEC source: 0001628280-26-047530 · wk-form4_1783458198.xml · nonDerivative · entry 4 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4 · price: 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 07, 2026 Filed Jul 7, 2026 21:03 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 28,228 | $12.00 | $338,736.00 |
DisclosureSEC source: 0001628280-26-047530 · wk-form4_1783458198.xml · nonDerivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,751,503 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 06, 2026 Filed Jul 7, 2026 21:03 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 41,772 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0001628280-26-047530 · wk-form4_1783458198.xml · derivative · entry 5 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 98,228 Underlying: Common Stock · 41,772 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F5 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 06, 2026 Filed Jul 7, 2026 21:03 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 41,772 | $42.09 | $1,758,183.48 |
DisclosureSEC source: 0001628280-26-047530 · wk-form4_1783458198.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| July 06, 2026 Filed Jul 7, 2026 21:03 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 41,772 | $12.00 | $501,264.00 |
DisclosureSEC source: 0001628280-26-047530 · wk-form4_1783458198.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,765,047 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| June 16, 2026 Filed Jun 18, 2026 20:13 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | GrantNonqualified Stock Option (Right to Buy) · Derivative | 237,175 | $0.00 Strike: $40.24 | $0.00 |
DisclosureSEC source: 0002080477-26-000012 · wk-form4_1781813622.xml · derivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 237,175 Underlying: Common Stock · 237,175 shares Expires 2036-06-15 F3 · derivative.exercise_date: 79,059 of the shares subject to this option will vest on June 16, 2027, 79,058 of the shares subject to this option will vest on June 16, 2028 and the remaining 79,058 of the shares subject to this option will vest on June 16, 2029, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date. Read SEC document |
| June 16, 2026 Filed Jun 18, 2026 20:13 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | GrantIncentive Stock Option (Right to Buy) · Derivative | 2,485 | $0.00 Strike: $40.24 | $0.00 |
DisclosureSEC source: 0002080477-26-000012 · wk-form4_1781813622.xml · derivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 2,485 Underlying: Common Stock · 2,485 shares Expires 2036-06-15 F2 · derivative.exercise_date: 829 of the shares subject to this option will vest on June 16, 2027, 828 of the shares subject to this option will vest on June 16, 2028 and the remaining 828 of the shares subject to this option will vest on June 16, 2029, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date. Read SEC document |
| June 16, 2026 Filed Jun 18, 2026 20:13 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | GrantCommon Stock | 232,977 | $0.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000012 · wk-form4_1781813622.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 743,939 F1 · shares: The amount represents restricted stock units ("RSUs") that vest as to 77,659 on June 16, 2027, 77,659 on June 16, 2028 and the remaining 77,659 on June 16, 2029, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date. Read SEC document |
| June 02, 2026 Filed Jun 4, 2026 20:37 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 70,000 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000010 · wk-form4_1780605422.xml · derivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 140,000 Underlying: Common Stock · 70,000 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| June 02, 2026 Filed Jun 4, 2026 20:37 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 70,000 | $42.36 | $2,965,200.00 |
DisclosureSEC source: 0002080477-26-000010 · wk-form4_1780605422.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $42.00 to $45.73. 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| June 02, 2026 Filed Jun 4, 2026 20:37 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 70,000 | $12.00 | $840,000.00 |
DisclosureSEC source: 0002080477-26-000010 · wk-form4_1780605422.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,793,275 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| May 11, 2026 Filed May 13, 2026 20:26 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionIncentive Stock Option (Right to Buy) · Derivative | 24,999 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000008 · wk-form4_1778703977.xml · derivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 0 Underlying: Common Stock · 24,999 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · derivative.exercise_date: The options are fully vested. Read SEC document |
| May 11, 2026 Filed May 13, 2026 20:26 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 24,999 | $12.00 | $299,988.00 |
DisclosureSEC source: 0002080477-26-000008 · wk-form4_1778703977.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 510,962 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. Read SEC document |
| May 05, 2026 Filed May 7, 2026 20:07 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 15,771 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0002080477-26-000006 · wk-form4_1778184416.xml · derivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 210,000 Underlying: Common Stock · 15,771 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F4 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| May 05, 2026 Filed May 7, 2026 20:07 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 15,771 | $47.92 | $755,746.32 |
DisclosureSEC source: 0002080477-26-000006 · wk-form4_1778184416.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $47.13 to $48.35. The price reported above reflects the weighted average sale 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| May 05, 2026 Filed May 7, 2026 20:07 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 15,771 | $12.00 | $189,252.00 |
DisclosureSEC source: 0002080477-26-000006 · wk-form4_1778184416.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,739,046 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| May 04, 2026 Filed May 5, 2026 12:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 54,229 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0001628280-26-030147 · wk-form4_1777983472.xml · derivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 225,771 Underlying: Common Stock · 54,229 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| May 04, 2026 Filed May 5, 2026 12:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 54,229 | $47.26 | $2,562,862.54 |
DisclosureSEC source: 0001628280-26-030147 · wk-form4_1777983472.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| May 04, 2026 Filed May 5, 2026 12:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 54,229 | $12.00 | $650,748.00 |
DisclosureSEC source: 0001628280-26-030147 · wk-form4_1777983472.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,777,504 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| April 15, 2026 Filed Apr 17, 2026 20:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 70,001 | $0.00 Strike: $12.00 | $0.00 |
DisclosureSEC source: 0001628280-26-025753 · wk-form4_1776457027.xml · derivative · entry 5 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 280,000 Underlying: Common Stock · 70,001 shares Expires 2026-08-02 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F5 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| April 15, 2026 Filed Apr 17, 2026 20:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 49,900 | $43.68 | $2,179,632.00 |
DisclosureSEC source: 0001628280-26-025753 · wk-form4_1776457027.xml · nonDerivative · entry 4 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Direct Disclosed balance after: 485,963 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $42.57 to $44.41. The price reported above reflects the weighted average sale 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. F4 · balance_after: Includes 12,000 shares of common stock, which are held jointly with the Reporting Person's spouse with right of survival. Read SEC document |
| April 15, 2026 Filed Apr 17, 2026 20:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 104,124 | $43.36 | $4,514,816.64 |
DisclosureSEC source: 0001628280-26-025753 · wk-form4_1776457027.xml · nonDerivative · entry 3 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,723,275 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $42.57 to $44.41. The price reported above reflects the weighted average sale 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| April 15, 2026 Filed Apr 17, 2026 20:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | SaleCommon Stock | 70,001 | $43.36 | $3,035,243.36 |
DisclosureSEC source: 0001628280-26-025753 · wk-form4_1776457027.xml · nonDerivative · entry 2 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,827,399 F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F3 · price: This transaction was executed in multiple trades throughout the day at prices ranging from $42.57 to $44.41. The price reported above reflects the weighted average sale 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. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| April 15, 2026 Filed Apr 17, 2026 20:17 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionCommon Stock | 70,001 | $12.00 | $840,012.00 |
DisclosureSEC source: 0001628280-26-025753 · wk-form4_1776457027.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: Plan reported Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,897,400 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F1 · kind: This transaction was effected pursuant to a previously established Rule 10b5-1 Plan adopted by the Reporting Person on December 29, 2025. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| March 30, 2026 Filed Apr 1, 2026 20:42 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Tax withholdingCommon Stock | 20,875 | $37.50 | $782,812.50 |
DisclosureSEC source: 0002080477-26-000004 · wk-form4_1775076159.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,827,399 F1 · shares: Represents shares that have been surrendered to the Company to satisfy tax withholding and remittance obligations in connection with the net settlement of restricted stock awards and does not represent a sale by the reporting person. F2 · ownership.direct: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| February 10, 2026 Filed Feb 12, 2026 21:33 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Tax withholdingCommon Stock | 50,100 | $41.33 | $2,070,633.00 |
DisclosureSEC source: 0002080477-26-000002 · wk-form4_1770932000.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 535,863 F1 · shares: Represents shares that have been surrendered to the Company to satisfy tax withholding and remittance obligations in connection with the net settlement of restricted stock awards and does not represent a sale by the reporting person. Read SEC document |
| December 23, 2025 Filed Dec 29, 2025 13:46 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | GiftCommon Stock | 2,000 | Not disclosed | Not disclosed |
DisclosureSEC source: 0002080477-25-000012 · wk-form4_1767016012.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Direct Disclosed balance after: 585,963 F1 · shares: Bona fide gift by Reporting Person of 2,000 shares of common stock to his son. The shares are subject to a lockup agreement entered into by the Reporting Person on December 11, 2025 (the "Lock-up Agreement"). The transferee has agreed to be bound by the terms of the Lock-up Agreement. F2 · price: Price is not applicable to acquisitions or dispositions resulting from bona fide gifts. F3 · balance_after: Includes 12,000 shares of common stock, which are held jointly with the Reporting Person's spouse with right of survival. Read SEC document |
| August 26, 2025 Filed Aug 28, 2025 20:33 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Tax withholdingCommon Stock | 192,220 | $33.90 | $6,516,258.00 |
DisclosureSEC source: 0002080477-25-000009 · wk-form4_1756413222.xml · nonDerivative · entry 1 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 1,848,274 F1 · shares: Represents shares that have been surrendered to the Company to satisfy tax withholding and remittance obligations in connection with the net settlement of restricted stock awards and does not represent a sale by the reporting person. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC. Read SEC document |
| August 15, 2025 Filed Aug 19, 2025 20:06 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 375,000 | $0.00 Strike: $16.14 | $0.00 |
DisclosureSEC source: 0001628280-25-040785 · wk-form4_1755633954.xml · derivative · entry 24 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 375,000 Underlying: Common Stock · 375,000 shares Expires 2031-09-09 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F6 · derivative.exercise_price: 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. F6 · shares: 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 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC Read SEC document |
| August 15, 2025 Filed Aug 19, 2025 20:06 UTC | MIAMI INTERNATIONAL HOLDINGS, INC. MIAX · Entity 4026 | Exercise / conversionNonqualified Stock Option (Right to Buy) · Derivative | 375,000 | $0.00 Strike: $16.14 | $0.00 |
DisclosureSEC source: 0001628280-25-040785 · wk-form4_1755633954.xml · derivative · entry 23 Gallagher Thomas P. · CIK 0002080477 · Director · Chairman & CEO 10b5-1 filing: No plan indicated Ownership: Indirect · By Gallagher Investments, LLC Disclosed balance after: 0 Underlying: Nonvoting Common Stock · 375,000 shares Expires 2031-09-09 Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event. F6 · derivative.exercise_price: 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. F6 · shares: 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 · derivative.exercise_date: The options are fully vested. F2 · ownership.nature: Mr. Gallagher maintains beneficial ownership, including dispositive and voting control, over Gallagher Investments, LLC Read SEC document |
Value uses the disclosed total when available, otherwise shares × reported transaction price. It is not an estimate of exercise cash cost or investment performance.