The Crab is the most extreme harmonic pattern, projecting its completion point far beyond X to the 161.8% extension of XA. It is designed to catch sharp reversals at deeply stretched extremes, where a move has run much further than usual and momentum is exhausted.
Defining ratios
- B retraces 38.2% to 61.8% of the XA leg.
- BC retraces 38.2% to 88.6% of AB.
- CD extends 261.8% to 361.8% of BC — a very long final leg.
- D projects to 161.8% of XA — the pattern's signature.
The Crab's hallmark is that long, sharp CD leg that drives D out to the 161.8% extension. Because the reversal is caught at such an extreme, the pattern can offer huge targets, but the extended move also means false completions are common.
Trading the Crab
Enter at D as the 161.8% zone shows rejection, with a stop just beyond D since it is already an extreme. The Crab can produce the best reward-to-risk of the harmonics because the stop is tight relative to the reversal target — but only if you wait for real confirmation and accept that fighting a strong move is risky by nature.
The Crab projects D to 161.8% of XA — an extreme reversal trade with excellent reward-to-risk but a high need for confirmation.