ETFs and the Flash Crash - CBS MoneyWatch.com

ETFs and the Flash Crash - CBS MoneyWatch.com: "Ironically, the allure of ETFs has always been their liquidity. (Indeed, the fact that investors can buy and sell them throughout the day is really the only point of differentiation between an ETF and a traditional index mutual fund.) But that liquidity ended up costing quite a few investors dearly. IndexUniverse.com for example, noted that hundreds of trades of the Rydex S&P Equal Weight ETF were made at prices between $10 and $30 per share, far below its $41.25 closing price. (Quite obviously, half of the people involved in those trades were very pleased. The other half paid dearly for the market’s glitch.)"