| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Casper Stephen P | Director | C/O MARKETAXESS HOLDINGS INC., 55 HUDSON YARDS, 15TH FLOOR, NEW YORK | /s/ Patrick Wilson, as Attorney-in-Fact for Stephen Casper | 09 Sep 2025 | 0001296969 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | MKTX | Common Stock, par value $0.003 per share | Sale | -$299K | -1.6K | -3.57% | $186.59 | 43.2K | 08 Sep 2025 | By family trust | |
| holding | MKTX | Common Stock, par value $0.003 per share | 9.99K | 08 Sep 2025 | Direct |