X0306 4 2022-01-31 0 0001278021 MARKETAXESS HOLDINGS INC MKTX 0001296466 McVey Richard M C/O MARKETAXESS HOLDINGS INC. 55 HUDSON YARDS, 15TH FLOOR NEW YORK NY 10001 1 1 0 0 Chairman & CEO Common Stock, par value $0.003 per share 2022-01-31 4 A 0 2300 0.00 A 732133 D Common Stock, par value $0.003 per share 2022-01-31 4 F 0 4032 344.48 D 728101 D Common Stock, par value $0.003 per share 2022-01-31 4 F 0 1321 344.48 D 726780 D Common Stock, par value $0.003 per share 2022-01-31 4 F 0 504 344.48 D 726276 D Common Stock, par value $0.003 per share 2022-01-31 4 F 0 285 344.48 D 725991 D Common Stock, par value $0.003 per share 2000 I By Immediate Family Members Stock Option (right to buy) 344.48 2022-01-31 4 A 0 7982 0.00 A 2028-01-31 Common Stock 7982 7982 D Represents a grant of restricted stock units pursuant to the Company's 2020 Equity Incentive Plan. The restricted stock units will vest in three installments of 34% on January 31, 2023, and 33% on each of January 31, 2024 and January 31, 2025. Represents the surrender of shares to the Company to satisfy Mr. McVey's tax withholding obligation upon the receipt of vested restricted stock units that had been previously deferred by Mr. McVey. Represents the surrender of shares to the Company to satisfy Mr. McVey's tax withholding obligation upon the vesting of shares of restricted stock previously granted to Mr. McVey. Represents the surrender of shares to the Company to satisfy Mr. McVey's tax withholding obligation upon the vesting of shares of restricted stock units previously granted to Mr. McVey. The stock options will vest in three installments of 34% on January 31, 2023, and 33% on each of January 31, 2024 and January 31, 2025. /s/ Jason Edelstein, as Attorney-in-Fact for Richard M. McVey 2022-02-02