In technical analysis, an Evening Star is a three candle pattern that is used by chartists to signal the end of an uptrend and the beginning of a reversal.
Evening Stars are typically found at the top of upward trending markets.
Firstly you have a large upward candle, this is followed by a small candle, either upward or downward, with a closing price that is above the previous candle, finally a large downward candle that opens below the second one and closes at around the midpoint of the first candle.
Evening stars signal a bull move that is running out of steam. As the buying power of the bulls begins to wane, this gives the bears a chance to reassert their dominance.