In 2005, approximately 30 percent of total CME volume came from "open outcry" trading — a face-to-face, auction-like process that takes place in what are called trading "pits". Pits are special tiered areas on the trading floors that look a little bit like bleachers, built into the floor and traditionally arranged in the shape of an octagon.

In floor trading, the traders stand in the pits making bids and offers on a specific commodity. Generally, only one commodity is traded in each pit and that pit is the only location on the floor where trading in that commodity may take place. Options on each contract are traded in adjoining pits. To accommodate its many different contracts, CME offers pit trading on two floors.

The pits are surrounded by rows of workstations or "desks", where orders from individual investors as well as large commercial users are received by phone or computer from around the world. These orders are carried to the trading pits by runners or "flashed" to the pits by hand signals.

Each pit is divided into segments designated for different contract delivery months. The lead month (the month closest to expiration — and usually the most actively traded) requires the most space. In the CME S&P 500 futures pit, for example, the lead month takes up about 90% of the pit. The back months (those furthest from expiration and usually the least actively traded) take up just one small section of the pit.

Electronic tickers and display boards located all around on the walls add to the vibrancy of the trading floors. For example, huge electronic tickers on the south end of both CME floors display price quotes from the New York Stock Exchange (NYSE), the Chicago Board of Trade (CBOT), and the various New York futures exchanges.

The date and time are displayed on electronic boards in each corner of the trading floors. Above the time there is a letter or symbol that signifies the time bracket. Every 15 minutes a siren sounds and a new bracket letter appears. The time brackets serve as part of a paper trail audit for the exchange and the members in case a question arises. The floor brokers and floor traders are required to write the time bracket letter or symbol on an executed order ticket. This bracketing system therefore helps to pinpoint within a fifteen-minute range the time that a trade took place.

Other displays provide up-to-the-minute information such as the latest trade figures, cash (spot) market prices, news about the exchange, and various announcements, such as the presence of VIPs visiting the exchange.



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