A bear is a person who has a pessimistic view of the direction of asset prices. The concept is most commonly applied to investors who attempt to profit from an expected downward spiral in securities prices. A bear may have a pessimistic view of the entire economy, of a specific market, or of the prospects of just a single company. The most common trading strategy of a bear investor is to sell short, which means that the person borrows shares and sells them at the current price, hoping to buy them back when the price eventually declines.
The opposite of a bear investor is a bull, who has an optimistic view of market conditions. The opposing actions of bulls and bears result in market prices.