The Chicago Board of Trade Building at night.Chicago has the third largest gross metropolitan product in the nation — approximately $442 billion according to 2007 estimates.32 The city has also been rated as having the most balanced economy in the United States, due to its high level of diversification.33 Chicago was named the fourth most important business center in the world in the MasterCard Worldwide Centers of Commerce Index.34 Additionally, the Chicago metropolitan area recorded the greatest number of new or expanded corporate facilities in the United States for six of the past seven years.35 In 2006, Chicago placed 10th on the UBS list of the world's richest cities.

Chicago is a major financial center with the second largest central business district in the U.S. The city is the headquarters of the Federal Reserve Bank of Chicago (the Seventh District of the Federal Reserve). The city is also home to three major financial and futures exchanges, including the Chicago Stock Exchange, the Chicago Board Options Exchange (CBOE), and the Chicago Mercantile Exchange (the "Merc"), which includes the former Chicago Board of Trade (CBOT). Chicago and the surrounding areas also house many major brokerage firms and insurance companies, such as Allstate and Zurich North America. The city and its surrounding metropolitan area are home to the second largest labor pool in the United States with approximately 4.25 million workers.37 Chicago has the largest high-technology and information-technology industry employment in the United States.38
 Manufacturing, printing, publishing, and food processing also play major roles in the city's economy. Several medical products and services companies are headquartered in the Chicago area, including Baxter International, Abbott Laboratories, and the Healthcare Financial Services division of General Electric. Moreover, the construction of the Illinois and Michigan Canal, which helped move goods from the Great Lakes south on the Mississippi River, and of the railroads in the 19th century made the city a major transportation center in the United States. In the 1840s, Chicago became a major grain port, and in the 1850s and 1860s Chicago's pork and beef industry expanded. As the major meat companies grew in Chicago many, such as Armour and Company, created global enterprises. Though the meatpacking industry currently plays a lesser role in the city's economy,39 Chicago continues to be a major transportation and distribution center. Early in the 20th Century, Chicago was part of the automobile revolution, hosting the brass era car builder Bugmobile, which was founded there in 1907.40
 Chicago is also a major convention destination. The city's main convention center is McCormick Place. With its four interconnected buildings, it is the third largest convention center in the world. Chicago also ranks third in the U.S. (behind Las Vegas and Orlando) in number of conventions hosted annually.41 In addition, Chicago is home to eleven Fortune 500 companies, while the metropolitan area hosts an additional 21 Fortune 500 companies.42 The state of Illinois is home to 66 Fortune 1000 companies.43 Chicago also hosts 12 Fortune Global 500 companies and 17 Financial Times 500 companies. The city claims one Dow 30 company as well as aerospace giant Boeing, which moved its headquarters from Seattle to the Chicago Loop in 2001.