Shark and 5-0 Patterns

The newest members of the harmonic family pivot off a different leg — opening up setups the classics miss.

The Shark and 5-0 patterns are the most recent additions to harmonic trading, formalized by Scott Carney in the 2000s. Both differ from the Gartley family in a crucial way: their defining ratios are measured from the BC leg rather than the XA leg. This shifts the focus to the final two swings and produces reversals where classic structures do not qualify.

The Shark pattern

The Shark is a five-point pattern where the defining ratio is the extension of BC:

X to A — initial impulse leg.
A to B — retraces 0.382 to 0.618 of XA.
B to C — retraces 1.13 to 1.618 of AB (extends beyond A or B).
C to D — completes at 0.886 retracement of BC (some variants use 1.13 extension of BC).

The signature rule: D completes at 0.886 of the BC leg. The Shark does not require the XA measurement to align, making it applicable in markets where the prior leg is ambiguous.

Trading the Shark

Entry: at the 0.886 retracement of BC, wait for reversal confirmation.

Stop: just beyond C. If price extends beyond C, the pattern is invalid.

Targets:

Target 1: 0.382 retracement of CD.
Target 2: 0.618 retracement of CD.
Target 3: the origin of the BC leg (point B).

The 5-0 pattern

The 5-0 is a corrective pattern that completes at the 0.50 retracement of BC:

X to A — initial leg.
A to B — retraces 1.13 to 1.618 of XA.
B to C — retraces 1.618 to 2.24 of AB.
C to D — completes at 0.50 retracement of BC.

The signature rule: D retraces exactly 0.50 of the BC leg. The 5-0 typically appears as a complex corrective structure rather than a clean trend reversal, and its 0.50 completion makes it one of the shallower harmonic entries.

Side-by-side

Pattern	Defining leg	Completion ratio	Stop
Shark	BC	0.886 of BC	Beyond C
5-0	BC	0.50 of BC	Beyond C

Classic harmonics (Gartley, Bat, Butterfly, Crab) all key off the XA leg. When the XA leg is irregular, they cannot form. The Shark and 5-0, by pivoting off BC, fill that gap — identifying reversal zones in markets the classics cannot reach.

Trading the 5-0

Entry: at the 0.50 retracement of BC, wait for a reversal bar (do not front-run). Stop: just beyond C. Targets: 0.382 and 0.618 retracements of CD.

Strengths, pitfalls, and context

Strengths: capture reversals where XA-based patterns cannot form; defined stops and targets; useful in corrective markets. Pitfalls: less statistically validated than the classics (treat as secondary), the 5-0's 0.50 completion is shallow, and misidentifying the BC leg is the most common error.

Sharks and 5-0s work best at higher-timeframe levels with confluence (support/resistance, moving averages, divergence). Because they are less self-fulfilling than Gartleys, do not trade them in isolation. And measure the BC leg precisely — the defining ratio is BC, not XA.

Next: the PRZ (Potential Reversal Zone) and stop-loss discipline that ties all harmonic patterns together.