Philadelphia Stock Exchange options, and a number of FX options. The PHLX has more than 16% of United States market share in exchange-listed stock and ETF options trading. The exchange's normal trading sessions are from 9:30 am to 4:00 pm on all days of the week except Saturdays, Sundays and holidays declared by the exchange in advance. 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
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