Crab Pattern — what it is and how to use it in trading
Definition
The Crab pattern is a harmonic XABCD figure with the deepest point D extension among all patterns the builder recognizes — point D travels substantially further past point X than a Butterfly's.
How it works in the builder
crab_bullish/crab_bearish use left/right/tolerance parameters — the same mechanism, but with the most "aggressive" set of extension ratios in the whole harmonic group.
What it looks like on the chart
The figure looks even more stretched than a Butterfly — the final C-D leg is noticeably longer than the figure's earlier legs.
Typical use
Like the other harmonics, point D is used as a potential reversal zone after a strong extended move — usually with an extra confirmation, such as a divergence or a candlestick pattern right at point D.
Common pitfalls
Because of its deep extension, a Crab forms less often than the other harmonics and requires a genuinely strong impulsive move — on a ranging market the figure is rarely found at all.
This block is available in the strategy builder
137 no-code blocks — build an entry condition with this term and test it on history
Historical results do not guarantee future ones. The service is an informational and analytical tool, not an individual investment recommendation; trades are not executed.