how is an etf different from an index fund 
an index fund usually refers to a mutual fund that tracks an index an index etf is constructed in much the same way and will hold the stocks of an index tracking it however the difference between an index fund and an etf is that an etf tends to be more cost effective and liquid than an index mutual fund you can also buy an etf from a broker who will execute the trade throughout the trading day while a mutual fund trades via a broker only at the close of each trading day 