contrarian

Anyone who thinks that most of what the public believes is wrong would be called a contrarian. And contrarian is a basic term in the vocabulary of investing. In fact, most successful investors often behave like contrarians by "buying low and selling high"—that is, buying stocks that are cheap because most investors put a low value on them but that have the possibility of rising, and selling stocks that most investors are valuing highly but that seem likely to decline. The word may be most common as an adjective; so you may express a contrarian opinion, hold a contrarian view, or pursue a contrarian investment strategy.