The swings in the market are up 1, 2 percent, down 3, 4 percent; it's chaos, depending on what you've bought on margin, you get cash-calls. So you get a lot of people jumping in and a lot of liquidity flowing ... into a stock or group of stocks. If the price on that falls at any point for say 5 or 6 percent, then all the people who bought that will get a call from their broker to say 'You need to pay some more cash or you need to sell right now.'.