A candle that opens and closes at very nearly the same price, leaving a cross rather than a body. Neither side finished the session in control.
The real body is negligible; the wicks carry the information. Long wicks on both sides mean a wide fight that settled nowhere. Short wicks mean a genuinely quiet day, which is a different thing entirely.
A doji is a question, not an answer. It gains meaning only from position: at the end of a long advance it suggests buyers have been met; in the middle of a range it means almost nothing.
Variants have their own names — the long-legged doji with wide wicks both ways, the dragonfly with only a lower wick, the gravestone with only an upper one. Each shifts the reading, and the last two are close relatives of the hammer and shooting star.
The common error is treating any doji as a reversal signal. Most are simply balanced days, and in quiet markets they appear constantly without consequence.
Illiquid counters produce dojis mechanically, since a stock that barely trades often closes where it opened. The liquidity filter on this scan removes the worst of these, but thin days still occur.
Because it is directionless, a doji cannot be acted on alone. It marks a point at which the following session's direction carries more weight than usual — nothing more.