Philadelphia Stock Exchange Philadelphia Stock Exchange Philadelphia Stock Exchange (PHLX), now known as NASDAQ OMX PHLX, is the oldest stock exchange in the United States. It is now owned by The NASDAQ OMX Group. Founded in 1790, the exchange was originally named the Board of Brokers of Philadelphia, also referred to as the Philadelphia Board of Brokers. In 1875, the Board of Brokers changed its name to the Philadelphia Stock Exchange. The exchange merged with the Baltimore Stock Exchange in 1949 and was named the Philadelphia-Baltimore Stock Exchange. It merged with the Washington Stock Exchange in 1954, becoming known as the Philadelphia-Baltimore-Washington Stock
National Stock Exchange (Jersey City, New Jersey) with plans to re-open trading at an unknown time. National Stock Exchange was founded March 1885 in Cincinnati, Ohio, as the Cincinnati Stock Exchange. In 1976, it closed its physical trading floor and became an all-electronic stock market. The Cincinnati Stock Exchange moved its headquarters to Chicago in 1995, and changed its name to the National Stock Exchange – NSX – on November 7, 2003. Owned by its members since inception, it demutualized in 2006. It later moved its headquarters to Jersey City, New Jersey. In September 2011, CBOE Stock Exchange (CBSX) entered into an agreement to acquire the National