a basket of securities that is traded, like individual stocks, on an exchange
a bite-size version that gives you all the benefits of index investing, with the handiness -- and costs -- associated with owning an individual stock
a miniature mutual fund, a low-cost basket of stocks that tracks an index
a mutual fund that trades like a single stock
an index fund that trades like a single stock
a stock market security that generally tracks an index, such as NASDAQ, or a group of stocks
An exchange-traded fund is an index fund which is traded on the stock market. Some common ETFs are the Nasdaq-100 Index Tracking Stock (QQQ), which tracks the Nasdaq-100 and Standard & Poor's Depositary Receipts (SPY), which tracks the S & P 500.
The broad class of funds, excluding closed-end funds, which trade throughout the day over an exchange. ETFs have low annual expenses, but you must pay commissions to trade them. ETFs do not redeem shares for cash, and thus do not need to sell securities (possibly realizing capital gains) to pay investors who redeem their shares. They are typically more tax-efficient than mutual funds. Unlike closed-end funds, ETFs market prices usually closely track their NAVs. Most ETFs are index funds.
An investment company, typically a mutual fund or unit investment trust, whose shares are traded intraday on stock exchanges at market-determined prices. Investors may buy or sell ETF shares through a broker just as they would the shares of any publicly traded company.
A basket of securities designed to track an index that trades like a stock and is listed on an exchange.
Exchange-traded funds (or ETFs) are closed-ended collective investment schemes, traded as shares on most global stock exchanges. Typically, ETFs try to replicate a stock market index such as the S&P 500 (http://finance.yahoo.com/q?s=spy SPY) or Hang Seng Index, a market sector such as energy or technology, or a commodity such as gold or petroleum.