The National Stock Exchange is a stock exchange located in Chicago, Illinois. It was founded in 1885 in Cincinnati, Ohio, as the Cincinnati Stock Exchange. In 1976, it closed its physical trading floor and became the United States' first all-electronic stock market. The Cincinnati Stock Exchange moved its headquarters to Chicago in 1995, and changed its name to the National Stock Exchange in November of 2003.
The National Stock Exchange is said to handle 20% of all trading in NASDAQ-listed issues.