The Piercing Line is a bullish two-candlestick reversal pattern that forms after a downtrend: the first candle is bearish, and the second is bullish, opening below the previous low and closing above the midpoint of the first candle's body. It suggests that buying pressure is overcoming selling pressure and may signal a trend reversal, but traders typically look for confirmation from subsequent price action or volume before entering a trade.
Candlestick Basics
Candlesticks, Japanese - Technical Analysis from A to Z