We've gone round and round on this previously elsewhere, some people drawing close parallels between index funds and Spiders. They do track closely from day to day in price. The principal difference, as I see it, has to do with your individual investment objective if you are not in a tax deferred situation. Index funds have low expense ratios, but they are recurring. That is, you pay the fee each year. That .48% fee can compound to a sizable sum over perhaps 15 or 20 years. The Spiders, on the other hand, when held over a comparable period of time, have broker fees for buying and selling, but no annual additional expenses. So a 1% or 2% one time brokerage cost would be less over time than annual fees! Any comments?