Listed options contracts trade on one of seven exchanges. The table breaks down the options volume for each exchange for trading on April 27, 2009. The International Securities Exchange [ISE] and the Chicago Board Options Exchange [CBOE] are the two largest and, on a typical day, account for nearly two-thirds of the overall volume (However, ISE was hit with a system outage Monday and therefore the volume on April 27 is less than normal.). The Philadelphia Stock Exchange [PHLX], the American Stock Exchange [AMEX], NYSE-Arca [NYSE], the NASDAQ [NDAQ], and the Boston Options Exchange [BOX] also list puts and calls.


Source: Options Clearing Corporation (optionsclearing.com)