Bull and bear markets can vary in duration, with no fixed timeline. Bull markets typically last longer than bear markets, lasting on average for several months to years. These periods are characterized by rising stock prices and investor confidence. On the other hand, bear markets are generally shorter but can be more intense. They can last anywhere from a few weeks to a couple of years, and are marked by declining stock prices and pessimism among investors. While there is no set time limit for these market phases, understanding their typical duration is crucial for making informed trading decisions.