Three white soldiers

Three consecutive long bullish candles, each opening within the previous candle's body and closing near its high, each close higher than the last.

The sequence describes persistent buying: every period opens inside the prior range — no gap-and-chase, just steady accumulation — and closes at the top. It is a picture of a trend with real participation behind it.

Both describe sustained one-sided control — useful for judging trend health, dangerous as a blind entry trigger.

Three black crows

The mirror: three consecutive long bearish candles, each opening within the prior body and closing near its low.

The trap

By the third candle, price has already moved a long way. This is the central problem with all continuation patterns: the pattern is easiest to recognise exactly when acting on it is most dangerous. Three white soldiers is also, not coincidentally, a textbook picture of an overextended short-term move that is due for a pullback.

So the practical uses are not "buy the third soldier":

As a trend-health check. Three soldiers with large bodies and small wicks means genuine participation. Three "soldiers" with long upper wicks means the buying is running into supply — which is a different picture wearing the same name.
As a warning about chasing. After a three-soldier sequence, entering long is entering after a large move with no pullback. If you must, wait for one.
As a context filter. A bearish reversal pattern appearing right after three white soldiers is more plausible than the same pattern in the middle of nowhere.

How to check this yourself

Find every three-soldier sequence on six months of daily data. For each, measure the move from the first open to the third close, then measure the pullback over the next five bars. You will find the pullbacks are frequent and often deep enough to stop out an entry made at the third close. That is the lesson, and it is worth more than the pattern.