AAPL, RIMM, GOOG, etc have the same pattern because they're part of the composition of the major indices, so their typical behavior is to track the major indice

AAPL, RIMM, GOOG, etc have the same pattern because they're part of the composition of the major indices, so their typical behavior is to track the major indices. If something causes the index to spike or fall, large volumes of whatever the index is composed of will traded.