Harmonic Patterns: Gartley, Butterfly and ABCD – Geometry Built From Fibonacci Ratios

Harmonic patterns (Gartley, butterfly, bat, crab, ABCD) are sequences of several turning points whose distances meet specific Fibonacci ratios. They look precise, but they rest on the same unproven idea as Fibonacci retracements.

What it is

H.M. Gartley described the basic pattern in 1935, and modern versions were developed by Larry Pesavento and Scott Carney, among others. The pattern has points X, A, B, C and D, and the D zone (the so-called potential reversal zone) comes from several overlapping ratios.

The ratio tolerance (e.g. 0.618 ± a few percent) means the pattern fits many price sequences.

How people use it

entering for a reversal in the D zone
pattern scanners in TradingView and MetaTrader
targets at retracements of the AD leg

What the research and evidence say

There's no independent research confirming that harmonic patterns work. Because they're based on Fibonacci ratios, they inherit the same problem: there's no evidence the market respects those numbers. Scanners find patterns that look convincing after the fact, and failed patterns quickly disappear from the chart.

Weaknesses

they rest on unproven ratios
the tolerances let you fit many patterns
scanners mostly show the “successful” patterns
complicated geometry creates an illusion of precision

What order flow shows

In the D zone, what matters is the same as at any potential reversal: whether aggression in the direction of the move is fading, whether absorption appears, whether the market rejects new prices. You can see that information in order flow, whether or not a butterfly can be drawn on the chart.

Indicators vs order flow

Every indicator and every pattern in this section is built from the same data: a candle's open, high, low, close and sometimes volume. They're derivatives of price, showing the effect rather than the cause. Order flow looks at what price is made of: who was buying and selling aggressively (delta), where limit orders were waiting (the order book) and at which prices the market accepted trade (the volume profile).

On CME futures this data is real and comes from one central market. Spot forex doesn't have it: platforms show tick volume, the number of price changes at a single provider.

To be fair: order flow isn't the Holy Grail. It takes learning, it can be noisy, big players hide some of their orders, and an edge only comes from a process and risk control. But it gives you information that simply isn't on a candlestick chart.

How to use it sensibly

count every pattern the scanner finds, not just the successful ones
don't treat geometry as evidence
in the reversal zone, watch what participants are doing

Glossary: Fibonacci retracements
Glossary: Absorption
Glossary: Exhaustion
Atlas of biases: The Texas sharpshooter fallacy
Atlas of biases: Cherry-picking
Atlas of biases: The clustering illusion
Order flow: Absorption on a real market: 51,300
Also under the microscope: Elliott Waves
Also under the microscope: Dow Theory
Also under the microscope: The Gann method

Frequently asked questions

What is the Gartley pattern?

A five-point XABCD sequence in which the legs meet specific Fibonacci ratios, and point D marks a potential reversal.

Do harmonic patterns work?

There's no independent evidence. They're based on Fibonacci ratios, whose effectiveness hasn't been confirmed.

Educational content, not investment advice. No signals, entries, stops or position sizes.