If investors insist on trying to time their moves in sharemarkets, said Warren Buffett almost 20 years ago, they should be fearful when others are greedy, and greedy only when others are fearful.

It is good contrarian stuff. And the time-honoured depiction of markets in the permanent push-pull grip of these two animal spirits has an enduring appeal because (nuance and caveats aside) it does actually explain a lot of market psychology quite neatly. The difficulty arises, as now, when greed and fear start defining themselves as the same thing.

Financial Times