Traders work on the floor of the New York Stock Exchange. Photo: Reuters/Lucas Jackson

Today it’s General Electric’s turn, down nearly 3% after JP Morgan analysts predicted a 20% decline in the Dow component. Yesterday it was Yum China, down to below $35 from $40 on a slight earnings miss, and O’Reilly Automotive, which fell by more than 20% on another small disappointment. The rest of the auto retailers sank with it for fear that Amazon would gobble up this sector as well.

This sort of response suggests that equity investors have stop-loss orders in place, and that trading bots trigger stampedes at the exit whenever a stock displays downside volatility.