A prolonged period (typically more than 400 days) in which market activity/ prices decline amid widespread pessimism or general negative sentiment. Bear market describes a downward market trend, whether it be the whole market or specific sectors or securities. A generally accepted measure of a bear market, as defined by the investment industry, is a price decline of 20% or more over a two-month period or more.

Markets usually fall into such a state of affairs when an economy is passing through a recession, or has entered high unemployment or rampant inflation periods. The severest bear market, in history, was the Great Depression which plagued the US in 1929 and intensified over the next decade.

Bear market is the opposite of bull market.