FLEX Specific Symbol Processing

Cboe has implemented a symbol definition mechanism for both simple and complex instruments on the FLEX feed. This significantly reduces the size of the FLEX feed and allows participants to use the same symbol handling mechanisms for the Cboe operated equities, options, and futures exchanges. Refer to the FLEX Instrument Definition and Complex FLEX Instrument Definition messages for more information.

The FLEX Instrument Definition or Complex FLEX Instrument Definition messages are sequenced messages that are sent when an instrument is created. If a user misses a definition message, that message can be recovered through either the GRP or SPIN Server.