Greed and fear

Greed and fear are supposed, together with herd instinct, to be the three main emotional motivators of stock markets and business behavior, and one of the cause of bull markets, bear markets and business cycles.Fact|date=September 2007

From a market saying to an academic research topic

The phrase, traditionally used by traders and market commentators, has become a topic of economic research about investor irrationalities (cognitive and emotional biases). Its effects on market prices and returns contradict, or at least moderate, the efficient market hypothesis.

Here are two examples of approaches:
* How those two alterning emotions work for traders, and how they can distort their decision process, has been the subject of neuroeconomics studies (1). More generally, those researches show some primacy of emotion over cognition in decision making.
* According to Hersh Shefrin, one of the key researchers in Behavioral economics, the phrase "hope and fear", although less colloquially used, would describe better those alterning excessive expectations by market players (2)

See also

* Emotional bias

References

* (1) [http://web.mit.edu/alo/www/Papers/lorepsteen4.pdf Fear and Greed in Financial Markets: A clinical study of Day-traders]
* (2) Shefrin, Hersh (2002) "Beyond Greed and Fear: Understanding behavioral finance and the psychology of investing." Oxford University Press