0001278021 2026-10-23 2026-10-23 0001278021 false MARKETAXESS HOLDINGS INC 8-K 2026-10-23 DE 001-34091 52-2230784 55 Hudson Yards 15th Floor New York NY 10001 (212) 813-6000 false false false false Common Stock, $0.003 par value MKTX NASDAQ false