Seth Klarman’s extraordinary and mysterious book Margin of Safety, Risk Averse Investing Strategies for the Thoughtful Investor has sold for $700 for used varieties with newer copies going for $2,500 to $4,000. His foremost investing premise is risk mitigation. He writes,

Investors may find it difficult to act as contrarians for they can never be certain whether or when they will be proven correct. Since they are acting against the crowd, contrarians are almost always initially wrong and likely for a time to suffer paper losses. By contrast, members of the herd are nearly always right for a period. Not only are contrarians initially wrong, they may be wrong more often and for longer periods than others because market trends can continue long past any limits warranted by underlying value.

Holding a contrary opinion is not always useful to investors, however. When widely held opinions have no influence on the issue at hand, nothing is gained by swimming against the tide. It is always the consensus that the sun will rise tomorrow, but this view does not influence the outcome. By contrast, when majority opinion does affect the outcome or the odds, contrary opinion can be put to use.