Warren Buffett: Human behaviour involved

“Markets will do crazy things over time. When Charlie and I were at Salomon, they’d always talk to us about five sigma events or six sigma events, and that’s fine if you’re talking about flipping coins, but it doesn’t mean anything when you get human behavior involved. And people do things that — intelligent people do things — very intelligent, educated people do things — that are totally irrational, and they do them en masse. And you saw it in 1998. You saw it in 2002. And you’ll see it again.”

—Warren Buffett (2007).