Key features
Many ETFs are designed to track a stock market index, such as the Nikkei Stock Average or TOPIX, or the price of a commodity such as gold or oil. Because they are listed on an exchange, anyone with a brokerage account can place buy and sell orders during trading hours, just as they would for a stock.
What to keep in mind
Many ETFs tend to have relatively low expense ratios, though the actual cost level varies by fund. A gap can also arise between the ETF's price and the index it tracks (tracking error), so it is advisable to check the tracked benchmark and the costs involved in the prospectus before purchasing.
