In practice
A marubozu opens at one extreme and closes at the other, so one side was in control from the first trade to the last. Traders read it as conviction, and it often appears as the candle that breaks a level or starts an impulse.
After one prints, many traders wait for a pullback into the candle's range rather than entering at its close.
What to watch for
Very large candles late in a move that has already run a long way can mark exhaustion rather than strength. Entering at the close of one also puts the logical stop a long way off.