A bullish pin bar pattern is a powerful reversal signal that usually forms after a downtrend or near a strong support zone, indicating rejection of lower prices. It is characterized by a small real body near the top of the candle and a long lower wick, which shows that sellers pushed the price down but buyers stepped in strongly and closed the price near the highs. This price rejection reflects buyer dominance and often signals the start of an upward move. The pattern becomes more reliable when it forms at key support, trendline support, or moving averages, and when followed by a bullish confirmation candle.