An exchange-Listed Security is a financial instrument that is traded through an exchange, such as the NYSE or Nasdaq. Exchange-listed securities include stocks, bonds, and other investment vehicles.Investors who wish to buy or sell exchange-listed securities must do so through an intermediary known as a broker. Brokers are registered with the exchanges and must comply with certain regulations. When buying or selling securities on behalf of their clients, brokers charge a commission.The price of an exchange-listed security is determined by supply and demand in the marketplace. Prices may fluctuate throughout the day in response to news events and other factors.