A bear market is a period when stock prices decline 20% or more from recent highs, typically accompanied by widespread pessimism and negative investor sentiment. Bear markets are often associated with economic recessions but can occur independently due to geopolitical events, policy changes, or financial crises. They usually develop gradually as economic conditions deteriorate, though sudden events like pandemics can trigger rapid bear markets. The average bear market in the US lasts about 9.6 months, compared to an average bull market of 2.7 years, meaning markets spend significantly more time going up than going down. During bear markets, defensive strategies like holding cash, investing in bonds, moving to value stocks, or using options for hedging tend to outperform growth-oriented approaches. Bear markets are a normal part of market cycles and historically have always been followed by recoveries, though the timing of the recovery is unpredictable.