what is an exchange traded fund etf 
an exchange traded fund etf is a pooled investment security that can be bought and sold like an individual stock etfs can be structured to track anything from the price of a commodity to a large and diverse collection of securities etfs can even be designed to track specific investment strategies various types of etfs are available to investors for income generation speculation and price increases and to hedge or partly offset risk in an investor s portfolio the first etf was the spdr s p 500 etf spy which tracks the s p 500 index 1investopedia zoe hansen