A bear market is a condition in the stock market characterized by a sustained period of falling stock prices. In a bear market, the overall trend of the market is downward, and a majority of stocks are declining in value. Bear markets are the opposite of bull markets, which are characterized by rising stock prices. The length and severity of a bear market can vary widely, but they are generally defined as a period of time where stock prices have fallen by 20% or more from their recent high. During a bear market, investors may become increasingly pessimistic about the future of the market, leading to reduced investment and lower demand for stocks. This in turn can further contribute to the decline in stock prices.