What harmonic patterns are
Harmonic patterns are chart shapes defined by Fibonacci ratios between price swings. A swing is a move from a local low to a local high, or the reverse. The idea is that some swing sequences repeat in measurable proportions. Where a pattern completes, some traders expect a possible reaction zone.
Each pattern is labelled with the points X, A, B, C and D. The legs between them are XA, AB, BC and CD. The pattern is defined by how far each leg travels compared with an earlier leg:
- B is measured as a retracement of XA.
- C is measured as a retracement of AB.
- D is measured against XA, either as a retracement or an extension, and against BC as an extension.
A retracement is a pullback inside a previous move. An extension is a projection beyond it. If these terms are new, read Fibonacci Retracement and Fibonacci Extension first.
A pattern is bullish when D forms at a low and bearish when D forms at a high. The shape is the same, only mirrored. "Bullish" here describes the shape. It is not a forecast.
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A drawn example (schematic, no prices)
Below is a bullish Gartley-style shape. It is drawn by hand to show the structure. It is not taken from any market.
- XA is the main impulse leg.
- B pulls back part of XA.
- C rises again but stays below A.
- D drops below B and stays above X.
The labels only describe the shape. They do not say what price will do next.
Ratio definitions of the main patterns
The exact ratios are listed on the Fibonacci tool's default levels and in the calculator below. This page describes where each point sits relative to those levels, so you can compare patterns without memorising a table.
Fill in the empty fields to see the result.
| Level | Price |
|---|---|
| 0% | 120 |
| 23.6% | 115.28 |
| 38.2% | 112.36 |
| 50% | 110 |
| 61.8% | 107.64 |
| 78.6% | 104.28 |
| 100% | 100 |
| 127.2% | 125.44 |
| 161.8% | 132.36 |
| 261.8% | 152.36 |
Up swing: retracement = high − range × ratio, extension = low + range × ratio (range = high − low); a down swing is mirrored. The levels depend on which swing you pick; price often ignores them.
Use the tool to plot the retracement levels of XA. Then plot the extension levels of BC. D is valid only where the two sets of levels cluster.
Gartley pattern
- B retraces XA to the golden-ratio retracement level, the well-known level just past the middle of the tool.
- C retraces part of AB without passing A.
- D completes at a deeper retracement of XA, below the golden-ratio level but still inside X.
- CD is often close to AB in length. This is called an AB=CD structure.
The key feature of the Gartley pattern is that D never passes X.
Bat pattern
- B retraces less of XA than in a Gartley. It usually stays shallower than the middle level.
- C retraces part of AB.
- D completes at the deepest standard retracement of XA, very close to X but still inside it.
- The BC extension is usually larger than in a Gartley.
When traders search "bat pattern forex", the key point is this: a shallow B, then a very deep D.
Butterfly pattern
- B retraces deeper than in a Gartley, to the deepest standard retracement level of XA.
- C retraces part of AB.
- D goes beyond X. It is measured as an extension of XA, not a retracement.
Crab pattern (for comparison)
The Crab pattern is similar to the Butterfly, but D extends much further beyond X. It sits at one of the largest standard XA extensions.
Summary table
| Pattern | Depth of B in XA | Position of D | Measured as |
|---|---|---|---|
| Gartley | Golden-ratio retracement | Inside X | XA retracement |
| Bat | Shallow, below the middle level | Inside X, very close to it | Deep XA retracement |
| Butterfly | Deepest standard retracement | Beyond X | XA extension |
| Crab | Shallow to middle | Far beyond X | Large XA extension |
Drawing tools
You can build harmonic patterns with standard tools in MT4 and MetaTrader 5:
- Trendlines connect X, A, B, C and D so you can see the shape. See Trendlines.
- Fibonacci retracement drawn from X to A shows where B and an inside-X D should sit.
- Fibonacci retracement drawn from A to B checks the depth of C.
- Fibonacci expansion projects BC, and for Butterfly or Crab also projects XA beyond X.
- The D zone is the area where the XA and BC levels overlap. Many traders call it the potential reversal zone. Mark it as a range, not a single line.
Some charting platforms offer a dedicated XABCD drawing tool. It places the points and shows the ratios for you, but it does not choose the swings. Custom indicators that detect patterns automatically often use ZigZag pivots. ZigZag pivots can move after the fact, as explained in Repainting indicators and the ZigZag Indicator guide.
Sensitivity to swing choice
Harmonic patterns are very sensitive to where you place X, A, B and C. Small changes produce a different pattern or none at all.
- Wick or body. Measuring from candle wicks gives different ratios than measuring from closing prices. Pick one method and use it every time.
- Timeframe. A clean swing on a higher timeframe may be several swings on a lower one. See Multiple timeframes.
- Which low is X. Moving X to an earlier or later low can turn a Gartley into a Bat or a Butterfly.
- Tolerance. Real prices rarely hit a ratio exactly. Every allowed margin of error makes more shapes "qualify" and weakens the definition.
- ZigZag settings. A more sensitive setting creates more pivots and more candidate patterns.
To test whether your labels are honest, ask whether another trader using your written rules would mark the same points. If not, the pattern is mostly your interpretation. It helps to anchor the swings in Market structure and clear Support and resistance.
Failure modes
- D zone breaks. Price passes through the zone without reacting. A Gartley that passes X is no longer a Gartley.
- Pattern morphing. Traders relabel a failed Gartley as a Butterfly, then a Crab. Each relabel moves the "expected" zone, which makes the method impossible to test.
- Hindsight fitting. Patterns look neat on past charts because you pick the swings after you see the result. Live patterns are less clear.
- Repainting detection. Automatic scanners may show a pattern that disappears later when a pivot moves.
- News and gaps. Fast moves around data releases or at the weekly open can skip the zone entirely.
- Costs at D. Spread and slippage widen in fast markets. A tight zone can be missed or filled at a worse price.
- Confirmation bias. After drawing a pattern, traders tend to ignore evidence against it.
Harmonic shapes overlap with ideas in Elliott Wave and general Chart Patterns. They share the same weakness: subjective point selection.
Risk and the legal position in Pakistan
No pattern makes an outcome certain. Leveraged CFD and forex trading can lose money fast, including more than you planned if stops are skipped by gaps. Decide position size and an invalidation level before relying on any shape. Risk management covers this.
Pakistani readers should also know the official position. Per the SBP, remitting foreign exchange to overseas forex/margin/CFD platforms is not allowed through any payment channel (FERA s.5(1)). Per the SECP, offshore forex/CFD platforms operate without regulatory approval in Pakistan, and per the SECP, offshore platforms have no Pakistani licence or oversight and offer no legal protection or recourse. Details are on Law and regulators.
Frequent questions
Are harmonic patterns reliable?
No pattern is reliable by itself. Results depend on how you choose swings, on tolerance rules and on risk control. This page makes no claim about how often they work.
What is the difference between a Gartley and a Butterfly pattern?
In a Gartley, D completes inside X as a retracement of XA. In a Butterfly, D extends beyond X and is measured as an XA extension.
How is the Bat pattern different from the Gartley?
The Bat has a shallower B and a deeper D that sits very close to X. The Gartley's B sits at the golden-ratio retracement.
Do I need a special indicator?
No. Trendlines, Fibonacci retracement and Fibonacci expansion are enough. Automatic scanners are optional and may repaint.
Should I measure from wicks or closes?
Either can work if you apply it consistently. Mixing the two changes the ratios and can create patterns that are not really there.
Where can I check the exact Fibonacci levels?
Use the Fibonacci calculator on this page or the default levels in your platform's Fibonacci tool.