As in headline, not oral sex, is Barry Ritholtz, who, writing for Bloomberg, notes that one should, “Kiss Your Assets Goodbye When Certainty Reigns.”

His basic thesis is that when you have unanimity of opinion, the markets are almost always disastrously wrong:

History teaches that whenever the opposite occurs — when certainty overwhelms uncertainty — the herd tends to be wrong. In rare instances, when there is a near-total lack of uncertainty in the market, the outcome is usually a spectacular disaster.

It’s a good read, and probably a very good investment strategy.