The CAT NMS Plan definition of “CAT Executing Broker” may differ from the definition of executing broker used in other SRO rules or other contexts.

CAT Executing Broker is defined in Section 1.1 of the CAT NMS Plan.

For a transaction in an Eligible Security that is executed on an exchange, the CAT Executing Brokers are the Industry Member identified as being responsible for the order on the buy-side of the transaction and the Industry Member responsible for the sell-side of the transaction in the equity order trade event and option trade event in the CAT Data submitted to the CAT by the relevant exchange.

For a transaction in an Eligible Security that is executed otherwise than on an exchange and required to be reported to an equity trade reporting facility of FINRA, the CAT Executing Brokers are the Industry Member identified as the executing broker and the Industry Member identified as the contra-side executing broker in the TRF/ORF/ADF transaction data event in the CAT Data submitted to the CAT by FINRA. However, in those circumstances where there is a non-Industry Member identified as the contra-side executing broker in the TRF/ORF/ADF transaction data event or no contra-side executing broker is identified in the TRF/ORF/ADF transaction data event, then the Industry Member identified as the executing broker in the TRF/ORF/ADF transaction data event would be treated as CAT Executing Broker for the Buyer and for the Seller.

The identity of the CAT Executing Broker will be determined from transaction reports reported to the CAT by the exchanges or FINRA. 

• Under the Participant Technical Specifications, for transactions occurring on a Participant exchange, there is a field for the exchange to report the market participant identifier (“MPID”) of “the member firm that is responsible for the order on this side of the trade.” The Industry Members identified in these fields for the transaction reports are the CAT Executing Brokers for transactions executed on an exchange. 
   
• FINRA is required to report the MPID of the executing party as well as the MPID of the contra-side executing party. The Industry Members identified in these two fields for the tape-reported transaction reports are the CAT Executing Brokers for over-the-counter transactions. Non-tape reports (e.g., regulatory reports or clearing reports), are not used for CAT billing. For more details regarding CAT fees related to transactions on Alternative Trading Systems, see FAQ V25, and for more details on CAT fees related to transactions involving a non-FINRA member, see FAQ V26.