Three-Line Strike
Three candles in one direction, then a fourth that engulfs all three — and its reliable resolution is the opposite of what its name suggests.
Also called: 3 line strike · bullish three line strike · bearish three line strike
What it means
A bullish Three-Line Strike is three rising candles followed by one large down-candle that opens above the third close and closes below the first open, swallowing the whole run. The bearish variant is the mirror.
The counter-intuitive part is the direction. Bulkowski's statistical work found that the pattern most often resolves AGAINST the direction its name implies — the bullish-named formation tends to continue lower, and the bearish-named one higher. The naming describes the geometry of the three candles, not the outcome.
This makes it one of the few patterns where trading the obvious reading is systematically the wrong side, and where a tool that "corrects" the direction to the intuitive one is actively harmful.
How OptionLab Pro’s engine uses it
In the live engine
We resolve it counter-directionally, per Bulkowski: the `(Bear)` variant resolves BULLISH and the `(Bull)` variant resolves BEARISH. That is deliberate and documented as a never-change invariant, because it looks like a bug to anyone reading the code for the first time and has been "fixed" by well-meaning contributors elsewhere. A parity harness checks the Go and Python engines agree on it.
go/internal/engine/candles.go (Three-Line Strike, counter-directional)The common mistake
Where traders get this wrong
Taking the name at face value. The single most common error with this pattern is trading a bullish-named Three-Line Strike long. The second is a developer seeing the inverted mapping in code, assuming it is a typo, and flipping it.
Go deeper
There is a full lesson on this in the Academy, with an interactive widget and a Hindi translation.
Related terms
Educational and analytical content only. OptionLab Pro is not a SEBI-registered investment adviser or research analyst and does not give buy or sell recommendations. Derivatives trading carries a high risk of loss.