An investor who deliberately decides to go against the prevailing wisdom of other investors

• Person who doesn't jump on the bandwagon
• One who doesn't do what's expected

Wiktionary Word definitions in Wiktionary
n. 1 a person who expresses a contradicting viewpoint, especially one who denounces the majority persuasion 2 (context finance English) a financial investor who tends to have an opinion of market trends at variance with most others

WordNet Word definitions in WordNet
n. an investor who deliberately decides to go against the prevailing wisdom of other investors

Wikipedia Word definitions in Wikipedia
A contrarian is a person who takes up a contrary position, especially a position that is opposed to that of the majority, regardless of how unpopular it may be.

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1963, from contrary + -ian .\n\nTo be in opposition is not to be a nihilist. And there is no decent or charted way of making a living at it. It is something you are, and not something you do. [Christopher Hitchens, "Letters to a Young Contrarian," 2001]

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
contrarian \con*tra"ri*an\, a. [LL. contrarians, p. pr. of contrariare to oppose, fr. L. contrarius: cf. F. contrariant, p. pr. of contrarier to contradict. See Contrary .] taking an opposing view, especially a view opposite to that taken by the majority. ...