Exchange Traded Funds are traded in stock exchanges just like stocks are; an Exchange Traded Fund is a security granting ownership of a pool of stocks and bonds, known as the underlying assets. An ETF may be bought or sold at the closing of a trading day at its net asset value or throughout the trading day at a price close to its net asset value. Exchange Traded funds were first available in the United States in 1993 and in Europe in 1999.