A doji at the top of an uptrend often indicates indecision and possible exhaustion of buying momentum. It forms when the opening and closing prices are nearly the same, showing that buyers pushed prices higher but sellers also entered and prevented a strong close. After a sustained rise, this can be an early warning that the trend is weakening and a reversal or pullback may happen, especially if the next candle confirms weakness by closing lower. However, a doji alone is not a sell signal, so traders usually combine it with volume, resistance zones, and confirmation candles before making decisions.