Crashes

% drop	time of drop	close trading for
10% drop	before 2PM	one hour halt
10% drop	2PM - 2:30PM	half-hour halt
10% drop	after 2:30PM	market stays open
20% drop	before 1PM	halt for two hours
20% drop	1PM - 2PM	halt for one hour
20% drop	after 2PM	close for the day
30% drop	any time during day	close for the day