the market is illiquid and highly leveraged intra-day. even small like 15 billion 'market sell order' in one minute into the market will crash or kill off intra-day liquidity or halt market. there is not that much cash on the table to absorb that kind of liquidation in the open market in 5 minutes unload and liquidate everything at once.. mutual funds and retail investors who didn't participate in the day didn't lose anything. the market just gap down to support. and the investors didn't lose 1 trillion either..on paper they did. the losers or sacrificial lamb are the leveraged traders in the CME or futures or hedge funds who had leveraged hedged portfolios who were force to liquidate on intra-day margin calls. what it just proves is the evidence is more regulation on trading activity. as only a handful guys or firms can crash the market at will or because they can manipulate markets at extremes..and that the market riggable. http://ca.news.finance.yahoo.com/s/...says-authorities-probe-cause-stock-swoon.html