Hammer / Pin Bar
Candle with long lower wick - shows buyers absorbing the dip.
Hammer = small body at top, long lower wick (>=2x body). Forms at the end of a drop: price fell intraday but buyers bid it back. The longer the wick and higher the body, the stronger the signal. Pin bar = same pattern in a trend. Opposite (wick on top) is shooting star.
In plain words
A candle with a long leg below says: price dropped deep but buyers scooped it all back before the session ended.
Example
BTC Aug 5, 2024: daily hammer at 49k with wick to 45k after the Japan crash -> bounced to 60k in 3 weeks.
Also known as: pin bar, hammer, shooting star