Cow Herd Battles A Bear

The term herd is also applied metaphorically to human beings in social psychology, with the concept of herd behaviour. However both the term and concepts that underlie its use are controversial.
The term has acquired a semi-technical usage in behavioral finance to describe the largest group of market investors or market speculators who tend to 'move with the market,' or 'follow the general market trend.' This is at least a plausible example of genuine herding, though according to some researchers it results from rational decisions through processes such as information cascade and rational expectations. Other researchers, however, ascribe it to non-rational process such as mimicry, fear and greed contagion. "Contrarians" or contrarian investors are those who deliberately choose to invest or speculate counter to the "herd".