{"entity":{"type":"insider","cik":"0001375242","url":"/insider/0001375242","json_url":"/insider/0001375242.json","name":"Millet T Kelley","name_source":"as-filed","also_issuer":false,"cross_url":null},"coverage_statement":{"n_transactions":41,"n_filings":7,"first":"2008-03-12","last":"2015-08-20","span_basis":"filed_date"},"name_variants":[{"name":"Millet T Kelley","source":"filing","n_filings":7,"first_seen":"2008-03-12","last_seen":"2015-08-20"}],"transactions":[{"id":8791717,"accession":"0001179110-15-012405","txn_seq":2,"anchor":"line-2","filing_url":"/filing/0001179110-15-012405","line_url":"/filing/0001179110-15-012405#line-2","is_derivative":false,"issuer_cik":"0000920424","issuer_name":"INVESTMENT TECHNOLOGY GROUP, INC.","issuer_ticker":"ITG","issuer_name_source":null,"issuer_url":"/issuer/0000920424","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director","officer_title":null,"security_title":"Common Stock","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1000.0,"shares_display":"1,000","price_per_share":17.11,"price_display":"17.11","price_state":"stated","total_value":17110.0,"total_display":"17,110.00","shares_owned_after":10640.0,"shares_owned_after_display":"10,640","ownership_form":"D","is_10b5_1":null,"transaction_date":"2015-08-19","filed_date":"2015-08-20","scope":"insider"},{"id":8791716,"accession":"0001179110-15-012405","txn_seq":1,"anchor":"line-1","filing_url":"/filing/0001179110-15-012405","line_url":"/filing/0001179110-15-012405#line-1","is_derivative":false,"issuer_cik":"0000920424","issuer_name":"INVESTMENT TECHNOLOGY GROUP, INC.","issuer_ticker":"ITG","issuer_name_source":null,"issuer_url":"/issuer/0000920424","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director","officer_title":null,"security_title":"Common Stock","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1000.0,"shares_display":"1,000","price_per_share":17.53,"price_display":"17.53","price_state":"stated","total_value":17530.0,"total_display":"17,530.00","shares_owned_after":9640.0,"shares_owned_after_display":"9,640","ownership_form":"D","is_10b5_1":null,"transaction_date":"2015-08-18","filed_date":"2015-08-20","scope":"insider"},{"id":8833398,"accession":"0001209191-11-027711","txn_seq":2,"anchor":"line-2","filing_url":"/filing/0001209191-11-027711","line_url":"/filing/0001209191-11-027711#line-2","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"S","transaction_label":"Open-market sale","open_market":true,"acquired_disposed":"D","direction_word":"disposed","shares":35000.0,"shares_display":"35,000","price_per_share":22.07,"price_display":"22.07","price_state":"stated","total_value":772450.0,"total_display":"772,450.00","shares_owned_after":275629.0,"shares_owned_after_display":"275,629","ownership_form":"D","is_10b5_1":null,"transaction_date":"2011-05-10","filed_date":"2011-05-11","scope":"insider"},{"id":8833396,"accession":"0001209191-11-027711","txn_seq":1,"anchor":"line-1","filing_url":"/filing/0001209191-11-027711","line_url":"/filing/0001209191-11-027711#line-1","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"S","transaction_label":"Open-market sale","open_market":true,"acquired_disposed":"D","direction_word":"disposed","shares":20900.0,"shares_display":"20,900","price_per_share":22.01,"price_display":"22.01","price_state":"stated","total_value":460009.0,"total_display":"460,009.00","shares_owned_after":310629.0,"shares_owned_after_display":"310,629","ownership_form":"D","is_10b5_1":null,"transaction_date":"2011-05-09","filed_date":"2011-05-11","scope":"insider"},{"id":8996282,"accession":"0001209191-11-026731","txn_seq":1,"anchor":"line-1","filing_url":"/filing/0001209191-11-026731","line_url":"/filing/0001209191-11-026731#line-1","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"S","transaction_label":"Open-market sale","open_market":true,"acquired_disposed":"D","direction_word":"disposed","shares":67196.0,"shares_display":"67,196","price_per_share":22.06,"price_display":"22.06","price_state":"stated","total_value":1482343.76,"total_display":"1,482,343.76","shares_owned_after":331529.0,"shares_owned_after_display":"331,529","ownership_form":"D","is_10b5_1":null,"transaction_date":"2011-05-05","filed_date":"2011-05-06","scope":"insider"},{"id":7309882,"accession":"0001209191-10-030581","txn_seq":1,"anchor":"line-1","filing_url":"/filing/0001209191-10-030581","line_url":"/filing/0001209191-10-030581#line-1","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":2000.0,"shares_display":"2,000","price_per_share":13.8564,"price_display":"13.86","price_state":"stated","total_value":27712.8,"total_display":"27,712.80","shares_owned_after":325531.0,"shares_owned_after_display":"325,531","ownership_form":"D","is_10b5_1":null,"transaction_date":"2010-05-25","filed_date":"2010-05-26","scope":"insider"},{"id":6088316,"accession":"0001209191-09-039535","txn_seq":1,"anchor":"line-1","filing_url":"/filing/0001209191-09-039535","line_url":"/filing/0001209191-09-039535#line-1","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1000.0,"shares_display":"1,000","price_per_share":9.99,"price_display":"9.99","price_state":"stated","total_value":9990.0,"total_display":"9,990.00","shares_owned_after":275065.0,"shares_owned_after_display":"275,065","ownership_form":"D","is_10b5_1":null,"transaction_date":"2009-08-05","filed_date":"2009-08-06","scope":"insider"},{"id":3617933,"accession":"0001209191-08-059156","txn_seq":15,"anchor":"line-15","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-15","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":2102.0,"shares_display":"2,102","price_per_share":5.65,"price_display":"5.65","price_state":"stated","total_value":11876.3,"total_display":"11,876.30","shares_owned_after":183299.0,"shares_owned_after_display":"183,299","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617931,"accession":"0001209191-08-059156","txn_seq":14,"anchor":"line-14","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-14","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1118.0,"shares_display":"1,118","price_per_share":5.66,"price_display":"5.66","price_state":"stated","total_value":6327.88,"total_display":"6,327.88","shares_owned_after":184417.0,"shares_owned_after_display":"184,417","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617929,"accession":"0001209191-08-059156","txn_seq":13,"anchor":"line-13","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-13","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":906.0,"shares_display":"906","price_per_share":5.63,"price_display":"5.63","price_state":"stated","total_value":5100.78,"total_display":"5,100.78","shares_owned_after":180497.0,"shares_owned_after_display":"180,497","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617927,"accession":"0001209191-08-059156","txn_seq":12,"anchor":"line-12","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-12","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":900.0,"shares_display":"900","price_per_share":5.55,"price_display":"5.55","price_state":"stated","total_value":4995.0,"total_display":"4,995.00","shares_owned_after":178591.0,"shares_owned_after_display":"178,591","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617925,"accession":"0001209191-08-059156","txn_seq":11,"anchor":"line-11","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-11","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":700.0,"shares_display":"700","price_per_share":5.68,"price_display":"5.68","price_state":"stated","total_value":3976.0,"total_display":"3,976.00","shares_owned_after":185691.0,"shares_owned_after_display":"185,691","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617923,"accession":"0001209191-08-059156","txn_seq":10,"anchor":"line-10","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-10","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":700.0,"shares_display":"700","price_per_share":5.64,"price_display":"5.64","price_state":"stated","total_value":3948.0,"total_display":"3,948.00","shares_owned_after":181197.0,"shares_owned_after_display":"181,197","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617921,"accession":"0001209191-08-059156","txn_seq":9,"anchor":"line-9","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-9","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":700.0,"shares_display":"700","price_per_share":5.56,"price_display":"5.56","price_state":"stated","total_value":3892.0,"total_display":"3,892.00","shares_owned_after":179291.0,"shares_owned_after_display":"179,291","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617919,"accession":"0001209191-08-059156","txn_seq":8,"anchor":"line-8","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-8","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":600.0,"shares_display":"600","price_per_share":5.69,"price_display":"5.69","price_state":"stated","total_value":3414.0,"total_display":"3,414.00","shares_owned_after":186291.0,"shares_owned_after_display":"186,291","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617917,"accession":"0001209191-08-059156","txn_seq":7,"anchor":"line-7","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-7","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":574.0,"shares_display":"574","price_per_share":5.67,"price_display":"5.67","price_state":"stated","total_value":3254.58,"total_display":"3,254.58","shares_owned_after":184991.0,"shares_owned_after_display":"184,991","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617915,"accession":"0001209191-08-059156","txn_seq":6,"anchor":"line-6","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-6","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":400.0,"shares_display":"400","price_per_share":5.81,"price_display":"5.81","price_state":"stated","total_value":2324.0,"total_display":"2,324.00","shares_owned_after":187291.0,"shares_owned_after_display":"187,291","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617914,"accession":"0001209191-08-059156","txn_seq":5,"anchor":"line-5","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-5","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":400.0,"shares_display":"400","price_per_share":5.54,"price_display":"5.54","price_state":"stated","total_value":2216.0,"total_display":"2,216.00","shares_owned_after":177691.0,"shares_owned_after_display":"177,691","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617912,"accession":"0001209191-08-059156","txn_seq":4,"anchor":"line-4","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-4","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":300.0,"shares_display":"300","price_per_share":5.7,"price_display":"5.70","price_state":"stated","total_value":1710.0,"total_display":"1,710.00","shares_owned_after":186591.0,"shares_owned_after_display":"186,591","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617910,"accession":"0001209191-08-059156","txn_seq":3,"anchor":"line-3","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-3","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":300.0,"shares_display":"300","price_per_share":5.62,"price_display":"5.62","price_state":"stated","total_value":1686.0,"total_display":"1,686.00","shares_owned_after":179591.0,"shares_owned_after_display":"179,591","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617908,"accession":"0001209191-08-059156","txn_seq":2,"anchor":"line-2","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-2","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":200.0,"shares_display":"200","price_per_share":5.72,"price_display":"5.72","price_state":"stated","total_value":1144.0,"total_display":"1,144.00","shares_owned_after":186791.0,"shares_owned_after_display":"186,791","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3617906,"accession":"0001209191-08-059156","txn_seq":1,"anchor":"line-1","filing_url":"/filing/0001209191-08-059156","line_url":"/filing/0001209191-08-059156#line-1","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":100.0,"shares_display":"100","price_per_share":5.76,"price_display":"5.76","price_state":"stated","total_value":576.0,"total_display":"576.00","shares_owned_after":186891.0,"shares_owned_after_display":"186,891","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-11-03","filed_date":"2008-11-05","scope":"insider"},{"id":3456019,"accession":"0001209191-08-017719","txn_seq":19,"anchor":"line-19","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-19","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":7210.0,"shares_display":"7,210","price_per_share":9.5,"price_display":"9.50","price_state":"stated","total_value":68495.0,"total_display":"68,495.00","shares_owned_after":153127.0,"shares_owned_after_display":"153,127","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456018,"accession":"0001209191-08-017719","txn_seq":18,"anchor":"line-18","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-18","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":5207.0,"shares_display":"5,207","price_per_share":9.53,"price_display":"9.53","price_state":"stated","total_value":49622.71,"total_display":"49,622.71","shares_owned_after":163984.0,"shares_owned_after_display":"163,984","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456017,"accession":"0001209191-08-017719","txn_seq":17,"anchor":"line-17","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-17","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":4950.0,"shares_display":"4,950","price_per_share":9.52,"price_display":"9.52","price_state":"stated","total_value":47124.0,"total_display":"47,124.00","shares_owned_after":158777.0,"shares_owned_after_display":"158,777","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456016,"accession":"0001209191-08-017719","txn_seq":16,"anchor":"line-16","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-16","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":4900.0,"shares_display":"4,900","price_per_share":9.55,"price_display":"9.55","price_state":"stated","total_value":46795.0,"total_display":"46,795.00","shares_owned_after":170560.0,"shares_owned_after_display":"170,560","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456015,"accession":"0001209191-08-017719","txn_seq":15,"anchor":"line-15","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-15","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":3732.0,"shares_display":"3,732","price_per_share":9.59,"price_display":"9.59","price_state":"stated","total_value":35789.88,"total_display":"35,789.88","shares_owned_after":178692.0,"shares_owned_after_display":"178,692","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456014,"accession":"0001209191-08-017719","txn_seq":14,"anchor":"line-14","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-14","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":3700.0,"shares_display":"3,700","price_per_share":9.64,"price_display":"9.64","price_state":"stated","total_value":35668.0,"total_display":"35,668.00","shares_owned_after":188660.0,"shares_owned_after_display":"188,660","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456013,"accession":"0001209191-08-017719","txn_seq":13,"anchor":"line-13","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-13","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":3163.0,"shares_display":"3,163","price_per_share":9.6,"price_display":"9.60","price_state":"stated","total_value":30364.8,"total_display":"30,364.80","shares_owned_after":181855.0,"shares_owned_after_display":"181,855","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456012,"accession":"0001209191-08-017719","txn_seq":12,"anchor":"line-12","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-12","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":3148.0,"shares_display":"3,148","price_per_share":9.49,"price_display":"9.49","price_state":"stated","total_value":29874.52,"total_display":"29,874.52","shares_owned_after":145917.0,"shares_owned_after_display":"145,917","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456011,"accession":"0001209191-08-017719","txn_seq":11,"anchor":"line-11","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-11","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":2100.0,"shares_display":"2,100","price_per_share":9.56,"price_display":"9.56","price_state":"stated","total_value":20076.0,"total_display":"20,076.00","shares_owned_after":172660.0,"shares_owned_after_display":"172,660","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456010,"accession":"0001209191-08-017719","txn_seq":10,"anchor":"line-10","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-10","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1962.0,"shares_display":"1,962","price_per_share":9.48,"price_display":"9.48","price_state":"stated","total_value":18599.76,"total_display":"18,599.76","shares_owned_after":142769.0,"shares_owned_after_display":"142,769","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456009,"accession":"0001209191-08-017719","txn_seq":9,"anchor":"line-9","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-9","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1737.0,"shares_display":"1,737","price_per_share":9.63,"price_display":"9.63","price_state":"stated","total_value":16727.31,"total_display":"16,727.31","shares_owned_after":184960.0,"shares_owned_after_display":"184,960","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456008,"accession":"0001209191-08-017719","txn_seq":8,"anchor":"line-8","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-8","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1676.0,"shares_display":"1,676","price_per_share":9.54,"price_display":"9.54","price_state":"stated","total_value":15989.04,"total_display":"15,989.04","shares_owned_after":165660.0,"shares_owned_after_display":"165,660","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456007,"accession":"0001209191-08-017719","txn_seq":7,"anchor":"line-7","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-7","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1368.0,"shares_display":"1,368","price_per_share":9.61,"price_display":"9.61","price_state":"stated","total_value":13146.48,"total_display":"13,146.48","shares_owned_after":183223.0,"shares_owned_after_display":"183,223","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456006,"accession":"0001209191-08-017719","txn_seq":6,"anchor":"line-6","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-6","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1200.0,"shares_display":"1,200","price_per_share":9.57,"price_display":"9.57","price_state":"stated","total_value":11484.0,"total_display":"11,484.00","shares_owned_after":173860.0,"shares_owned_after_display":"173,860","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456005,"accession":"0001209191-08-017719","txn_seq":5,"anchor":"line-5","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-5","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1123.0,"shares_display":"1,123","price_per_share":9.45,"price_display":"9.45","price_state":"stated","total_value":10612.35,"total_display":"10,612.35","shares_owned_after":140283.0,"shares_owned_after_display":"140,283","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456003,"accession":"0001209191-08-017719","txn_seq":4,"anchor":"line-4","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-4","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":1100.0,"shares_display":"1,100","price_per_share":9.58,"price_display":"9.58","price_state":"stated","total_value":10538.0,"total_display":"10,538.00","shares_owned_after":174960.0,"shares_owned_after_display":"174,960","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456002,"accession":"0001209191-08-017719","txn_seq":3,"anchor":"line-3","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-3","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":700.0,"shares_display":"700","price_per_share":9.51,"price_display":"9.51","price_state":"stated","total_value":6657.0,"total_display":"6,657.00","shares_owned_after":153827.0,"shares_owned_after_display":"153,827","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3456000,"accession":"0001209191-08-017719","txn_seq":2,"anchor":"line-2","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-2","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":524.0,"shares_display":"524","price_per_share":9.47,"price_display":"9.47","price_state":"stated","total_value":4962.28,"total_display":"4,962.28","shares_owned_after":140807.0,"shares_owned_after_display":"140,807","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"},{"id":3455999,"accession":"0001209191-08-017719","txn_seq":1,"anchor":"line-1","filing_url":"/filing/0001209191-08-017719","line_url":"/filing/0001209191-08-017719#line-1","is_derivative":false,"issuer_cik":"0001278021","issuer_name":"MARKETAXESS HOLDINGS INC","issuer_ticker":"MKTX","issuer_name_source":null,"issuer_url":"/issuer/0001278021","owner_cik":"0001375242","owner_name":"Millet T Kelley","owner_url":"/insider/0001375242","role":"Director, Officer (President)","officer_title":"President","security_title":"Common Stock, par value $0.003 per share","transaction_code":"P","transaction_label":"Open-market purchase","open_market":true,"acquired_disposed":"A","direction_word":"acquired","shares":500.0,"shares_display":"500","price_per_share":9.42,"price_display":"9.42","price_state":"stated","total_value":4710.0,"total_display":"4,710.00","shares_owned_after":139160.0,"shares_owned_after_display":"139,160","ownership_form":"D","is_10b5_1":null,"transaction_date":"2008-03-10","filed_date":"2008-03-12","scope":"insider"}],"next_cursor":null,"ledger_fault":false,"count":{"value":41,"kind":"exact"},"open_market_only":false,"composition":{"kind":"exact","rows":[{"code":"P","label":"Open-market purchase","n":38,"open_market":true},{"code":"S","label":"Open-market sale","n":3,"open_market":true},{"code":"M","label":"Option exercise","n":0,"open_market":false},{"code":"A","label":"Grant or award","n":0,"open_market":false},{"code":"F","label":"Tax withholding","n":0,"open_market":false},{"code":"D","label":"Disposition to the issuer","n":0,"open_market":false},{"code":"X","label":"In-the-money option exercise","n":0,"open_market":false}],"total":41},"affiliations":[{"type":"issuer","type_label":"ISSUER","cik":"0000920424","name":"INVESTMENT TECHNOLOGY GROUP, INC.","url":"/issuer/0000920424","role":"Director","n_filings":1,"first_seen":"2015-08-20","last_seen":"2015-08-20"},{"type":"issuer","type_label":"ISSUER","cik":"0001278021","name":"MARKETAXESS HOLDINGS INC","url":"/issuer/0001278021","role":"Director, Officer (President)","n_filings":6,"first_seen":"2008-03-12","last_seen":"2011-05-11"}],"order_statement":"Newest transaction date first, id breaking the tie.","canonical_url":"https://ebomi.com/insider/0001375242","retrieved_at":"2026-08-21T23:06:27+00:00","coverage":{"filings":1505395,"transactions":4290787,"issuers":28597,"insiders":152303,"first_filed_date":"2003-06-30","last_filed_date":"2026-08-20","last_ingest":"2026-08-21T05:23:33.898496+00:00","counts_are":{"filings":"estimate","transactions":"estimate","issuers":"estimate","insiders":"estimate"},"source":"SEC EDGAR Form 4 filings, parsed by ebomi","fault":false},"license":{"underlying_records":"US SEC filings are public records of the United States government and are not subject to copyright. The transactional facts in them are not ours to license.","this_presentation":"The parsing, normalisation, curation, and presentation are ebomi's own work.","grant":"undecided","grant_note":"The open licence for ebomi's own layer is an open owner decision (SPEC-20260731T1159Z open question 3: CC BY 4.0 or CC0 with a citation request). Until it is taken, no grant is asserted here.","citation_request":"Balogh, A. Insider trading. Scientific Data 10, 237 (2023)","url":"https://ebomi.com/license"},"fair_use":{"policy":"These JSON endpoints are open and unauthenticated. Please read them at a human pace, identify your client in the User-Agent header, and use the published dataset for bulk work rather than crawling page by page.","bulk_alternative":"doi:10.1038/s41597-023-02147-6"}}