Stock traders were stopped in their tracks Monday after sellers twice
It was the first time action has ever been halted in mid-session on the
The procedures were adopted after the 1987 market crash and updated last
*A 50-point drop in the Dow Jones industrial average means computerized
The opposite holds if the average has risen 50 points or more.
The restriction is removed if the industrial average recovers to within
*The "sidecar rule" is effective if the primary Standard & Poor's 500
*Trading is halted on all U.S. equity and futures markets for 30 minutes
*Trading is suspended for an hour if the Dow loss hits 550 points.