Quote from Get In Get Out:
What is the difference between IMM/IOM/GEM?
If you use google you'll find the following info or most brokers have the info...
* Chicago Mercantile Exchange® (CME) membership
Can execute trades in: Any contract listed at CME
Trading floor badge: Gold (indicates who they are and which products they can trade)
* International Monetary Market® (IMM) membership
Can execute trades in: Foreign exchange, interest rate and equity index futures, and all IMM and IOM (see below) futures and all options on futures contracts.
Trading floor badge: Green
* Index and Option Market® (IOM) membership
Can execute trades in: Index futures contracts, random length lumber contracts, all options on futures contracts, and all GEM products.
Trading floor badge: Blue
* Growth and Emerging Markets (GEM) membership
Can execute trades in: Various products, including those related to emerging market countries
Trading floor badge: Gray
Mark