{"transactions":[{"id":734608,"issuer":{"id":4026,"kind":"organization","name":"MIAMI INTERNATIONAL HOLDINGS, INC.","symbol":"MIAX"},"owners":[{"id":37363,"kind":"person","name":"Lozier Kenneth W.","position":1,"cik":"0002080877","reported_name":"Lozier Kenneth W.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Nonqualified Stock Option (Right to Buy)","published_at":"2026-06-17T20:43:15.000Z","date":"2026-06-16","kind":"grant","planned":false,"acquired":true,"shares":2571,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"1,285 of the shares subject to this option will vest on June 30, 2026, 643 of the shares subject to this option will vest on September 30, 2026 and the remaining 643 of the shares subject to this option will vest on December 31, 2026, subject to the Reporting Person's continued service to the Issuer or its subsidiaries through the applicable vesting date."}],"balance_after":2571,"derivative":{"exercise_price":40.24,"expiration_date":"2036-06-15","underlying":"Common Stock","underlying_shares":2571},"source":{"system":"sec-edgar","filing":"0002080877-26-000002","document":"wk-form4_1781728993.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/2080877/000208087726000002/wk-form4_1781728993.xml","form_type":"4"}},{"id":734607,"issuer":{"id":4026,"kind":"organization","name":"MIAMI INTERNATIONAL HOLDINGS, INC.","symbol":"MIAX"},"owners":[{"id":37363,"kind":"person","name":"Lozier Kenneth W.","position":1,"cik":"0002080877","reported_name":"Lozier Kenneth W.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-17T20:43:15.000Z","date":"2026-06-16","kind":"grant","planned":false,"acquired":true,"shares":4970,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F2","text":"The amount represents RSUs that vest on the last business day immediately preceding the 2027 annual meeting of stockholders, subject to the reporting person's continued service to the Issuer through the vesting date."}],"balance_after":8237,"source":{"system":"sec-edgar","filing":"0002080877-26-000002","document":"wk-form4_1781728993.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/2080877/000208087726000002/wk-form4_1781728993.xml","form_type":"4"}},{"id":734606,"issuer":{"id":4026,"kind":"organization","name":"MIAMI INTERNATIONAL HOLDINGS, INC.","symbol":"MIAX"},"owners":[{"id":37363,"kind":"person","name":"Lozier Kenneth W.","position":1,"cik":"0002080877","reported_name":"Lozier Kenneth W.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2026-06-17T20:43:15.000Z","date":"2026-06-15","kind":"grant","planned":false,"acquired":true,"shares":2267,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The amount represents restricted stock units (\"RSUs\") that fully vested on the date of grant. Each RSU represents a right to receive one share of the Issuer's common stock."}],"balance_after":3267,"source":{"system":"sec-edgar","filing":"0002080877-26-000002","document":"wk-form4_1781728993.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2080877/000208087726000002/wk-form4_1781728993.xml","form_type":"4"}},{"id":1065585,"issuer":{"id":4026,"kind":"organization","name":"MIAMI INTERNATIONAL HOLDINGS, INC.","symbol":"MIAX"},"owners":[{"id":37363,"kind":"person","name":"Lozier Kenneth W.","position":1,"cik":"0002080877","reported_name":"Lozier Kenneth W.","relationship":{"director":true,"officer":false,"ten_percent_owner":false,"other":false}}],"security":"Common Stock","published_at":"2025-08-15T20:48:22.000Z","date":"2025-08-13","kind":"purchase","planned":false,"acquired":true,"shares":1000,"price":23,"value":23000.0,"ownership":{"direct":true},"balance_after":1000,"source":{"system":"sec-edgar","filing":"0001628280-25-040556","document":"wk-form4_1755290897.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/2080877/000162828025040556/wk-form4_1755290897.xml","form_type":"4"}}]}