If you are using Heikin Ashi candles, a doji up high or down low usually means the trend whether uptrend or down trend is ending. Even the most explosive uptrend on a five minute chart will usually let you out gently if the next candle is a red following a doji. It is because all the candles heading higher have an upper wick and once a doji appears with the lower wick it tells you that sellers are entering the market while buyers are also still buying. Even if you look at Thursday in the above example it gave a doji as the last candle to say the selling had stopped and then the very next candle was a green on Friday's open to retest the weekly high followed by a doji as a second candle of the day to say the buying had stopped.
