3M lowers its earnings guidance and the stock caves. Blowing through its trend line, support zone, RSI/MACD lower, HUGE selling volume spike, etc. Not looking good for them now.
Each quarter, the "big boys" in the market have to report their positions because they're so large. Once those reports are made public, it shows what stocks they're adding to or reducing their exposure in and what stocks they've recently bought or completely sold out of.