A bull market is a condition in the stock market characterized by a sustained period of rising stock prices. In a bull market, the overall trend of the market is upward, and a majority of stocks are increasing in value. Bull markets are the opposite of bear markets, which are characterized by declining stock prices. The length and strength of a bull market can vary widely, but they are generally defined as a period of time where stock prices have risen by 20% or more from their recent low. During a bull market, investors may become increasingly optimistic about the future of the market, leading to increased investment and higher demand for stocks. This in turn can further contribute to the increase in stock prices.