The Dragonfly Doji candlestick formation is composed of a single candlestick bar. A Doji is simply a print that has the exact same open and close. With the open and close being exactly the same, there is no real body. However, being a Dragonfly Doji means, by definition, that the high is the same as the open and close, there is no upper body. If this prints at the bottom of a downtrend with a long lower body, this can be a very bullish signal.