Bull market: sustained rise of 20%+ from a recent low, typically over months. Sentiment is optimistic. New investors flood in. Every stock 'looks obvious in hindsight'.
Bear market: sustained fall of 20%+ from a recent high. Sentiment is fearful. Headlines predict doom. This is when experienced investors quietly build positions.
Historical Indian pattern: bull runs last longer (18–36 months average) but bear phases move faster (6–15 months). Both are inevitable.
Investor rule: never invest with money you'll need in the next 3 years. Bear markets can and will punish short-term horizons.