Tweezers Bottom
In an established downtrend, day-one is a black candle with a shaven bottom. The second day is a white hammer or doji with a long upper shadow. The essential element of this pattern is a series of candles that all share the same low. This could be the two days in the examples below, or a number of days that are not consecutive. After a protracted bearish move, this may provide a weak reversal signal but most traders will look for additional confirmation of a reversal.
Tweezers Bottom Candlestick Pattern