A joint venture between three Chicago-based futures exchanges that created an electronic exchange for trading futures, stocks, and exchange-traded funds. The venture began in November 2002. The joint venture members are Chicago Board Options Exchange (CBOE), Chicago Mercantile Exchange (CME), and Chicago Board of Trade (CBOT). Current members of these exchanges are automatically allowed to trade on OneChicago. In December 2002, the exchange began trading some single-stock futures.