The sculpture on top of the Chicago Board of Trade building is a statue of Ceres, the Roman goddess of grain. The wheat & corn she holds signifies the commodities that were traded by the market.
This Art Deco skyscraper, designed by Holabird & Root and completed in 1930, was the tallest building in Chicago until the Daley Center was built in 1965.
The center of the derivatives universe. Little known fact: the statue of Ceres on the roof has no face. They never thought anyone would be close enough to notice.