Dear CME Globex Customers,

Effective this Sunday, March 26 (for trade date Monday, March 27), CME is modifying FIX tag 375, the contra-party Subscriber ID, in CME Globex execution messages.

Currently, FIX tag 375 is disseminated in CME Globex execution messages with the six-character clearing firm identifier followed by the two-character CME iLink^® identifier (e.g. 'CME187M1'). To improve the anonymity of the CME markets, CME is replacing the two-character CME iLink identifier with two blanks (e.g. 'CME187 '). The clearing firm will still be identified in the first six characters of tag 375.

Please note: this change only applies to CME Globex execution messages.

This change to the CME Globex execution messages is currently available for testing in the CME certification environment.

If you have any questions or concerns, please contact your CME Globex Account Manager at 312.634.8700; or in Europe at +44.207.623.2550.

Thank you,

CME