Based in New York City, the NYSE is the largest stock exchange in the world (based on total market capitalization of listed securities). Also known as the “Big Board,” the NYSE dates back to 1792, and many of the oldest companies publicly traded in the US are listed on it. The opening and closing bells of the exchange mark beginning and end of the trading day. The opening bell sounds at 9:30 am Eastern Time and the closing bell at 4:00 pm Eastern Time. A series of mergers has given the NYSE its massive size and global presence.