Crab pattern
A five-point shape with a long final leg, where D reaches 161.8% of the first leg.
What it shows
The Crab was defined by Scott Carney. D extends well beyond X, to 161.8% of XA. The final leg CD is long compared with BC.
It is one of the deeper harmonic patterns, so the stretch from C to D is large.
How we find it
The same code that draws it on your chart follows these steps, with the same result every time.
- Find five alternating swing points X, A, B, C, D.
- B must be 38.2% to 61.8% of XA.
- C must be 38.2% to 88.6% of AB.
- D must be 161.8% of XA (±5%) and CD 224% to 361.8% of BC.
Starting values: Ratio tolerance ±5%; B 38.2% to 61.8% of XA; D 161.8% of XA. These are proposed and will be tuned on real price data before launch.
How to read it
- D is far beyond X.
- The CD leg is much longer than BC.
- Dashed lines show the ratio triangles.
Status labels you may see
| Label | What it means |
|---|---|
| Pattern forming | Points X through C match, D has not been reached. |
| Pattern complete | D matches the ratio rule. |
What cancels it
A close well beyond D (more than 5% past it).
What traders check next
- How long the CD leg is compared with BC.
- What happened at D.
- Whether other levels agree with D.
Limits
- The long final leg means large price distances.
- Tolerance lets many shapes qualify.
- Rarely tested in research.
Try it in forecastviz
- Open any ticker and choose Fibonacci and harmonic patterns → Crab pattern in the left menu.
- Switch between 6M, 1Y, 3Y to see how the picture changes.
- Compare with Deep Crab pattern and Butterfly pattern on the same chart.
Questions
Why Crab?
The shape looks like claws. It is a name.
How is it different from a Deep Crab?
A Deep Crab has a deeper B at 88.6% of XA.
Related trends
Further reading
- Boroden, Fibonacci Trading
- Carney, Harmonic Trading
- Murphy, Technical Analysis of the Financial Markets
Educational only. Not financial advice, and not a price forecast. Charts are drawn by code from past price data, which may be delayed.