What is "bull trap"

n. (context economics English) A temporary reverse in the downward trend of a share price that tempts some investors to buy

In economics, a Bull trap is an inaccurate signal that shows a decreasing trend in a stock or index has reversed and is now heading upwards, when in fact, the security will continue to decline.

It is seen as a trap because the bullish investor purchases the stock, thinking it will increase in value, but is trapped with a poor performing stock whose value is still falling.