Harmonic Patterns, Explained

Harmonic patterns are chart patterns defined by specific Fibonacci ratios between their price swings, used to identify potential reversal zones. The best known are the Gartley, bat, butterfly, and crab, each a five-point (XABCD) shape whose legs must hit particular ratio measurements to qualify. Traders use them to anticipate where a move might turn and to plan entries, stops, and targets around that zone. They are precise to draw but not magic; the ratios rarely land perfectly, and a valid pattern is a possibility, not a guarantee.

What harmonic patterns are

Harmonic patterns build on the idea that price moves in measurable, repeating proportions. Instead of loose shapes like a rough triangle, a harmonic pattern is only valid if the relationships between its swings match defined Fibonacci ratios. This makes them stricter and more rules-based than most chart patterns, which is part of their appeal to traders who want objective criteria.

The work of H.M. Gartley and later traders like Scott Carney formalized these shapes. Every harmonic pattern is a five-point structure labeled X, A, B, C, and D, made of four price legs (XA, AB, BC, CD). Point D is the important one: it marks the potential reversal zone, the area where the pattern predicts price may turn. The whole exercise is measuring the legs to see whether D lands where the ratios say it should.

The Fibonacci ratios that define them

The ratios come from the Fibonacci sequence and its derivatives. The commonly used values include 0.382, 0.500, 0.618, 0.786, 0.886, 1.13, 1.27, 1.414, 1.618, 2.24, 2.618, and 3.618. A pattern qualifies when each leg retraces or extends the previous one by a specific ratio from this set.

In practice you measure each leg against the one before it. For example, the B point of a Gartley must retrace a specific portion of the XA leg, and the D point must sit at a defined retracement or extension. Charting platforms like TradingView have harmonic drawing tools that snap to these ratios and show you whether a shape qualifies, which saves a lot of manual measuring. The important mental model is that harmonic trading is really about ratio relationships between swings, not about the visual outline.

The main harmonic patterns

Gartley

The Gartley is the original and most common. Its defining feature is a B point that retraces roughly 0.618 of the XA leg, with the D completion typically near a 0.786 retracement of XA. It sits relatively deep inside the initial move, so the reversal zone is not far from where price started, which some traders like for tighter stops.

Bat

The bat is similar in outline to the Gartley but with different ratios: a shallower B retracement (often around 0.382 to 0.500 of XA) and a deeper D completion near 0.886 of XA. Because D sits deeper, the bat aims to catch a reversal closer to the origin of the move, which can offer a favorable risk-reward if it holds.

Butterfly

The butterfly differs in an important way: its D point extends beyond the X origin rather than staying inside the move. D typically sits near a 1.27 extension of the XA leg. This means the pattern completes at a new extreme, so it is used to fade an overextended move rather than a pullback.

Crab

The crab is the most extended of the group. Its D point reaches out to roughly a 1.618 extension of the XA leg, far beyond the origin. Because the reversal zone is so stretched, the crab targets sharp turns after a strong, overextended push, and its extreme D can allow a tight stop just beyond it.

Tip: the family splits into two ideas. Gartley and bat complete inside the original move (retracement patterns), while butterfly and crab complete beyond it (extension patterns). Knowing which type you are looking at tells you whether you are fading a pullback or an overshoot.

How harmonic patterns are traded

The trading logic is consistent across all four. The reversal is expected at point D, so:

• Entry: traders look to enter near the D completion zone, ideally waiting for a confirming signal (a reversal candle, a momentum shift) rather than buying or selling the exact ratio blindly.
• Stop: placed just beyond the D point, since a clean break past D means the pattern has failed. The extension patterns (crab, butterfly) can allow tighter stops because D is a sharp extreme.
• Targets: commonly set at Fibonacci retracements of the completed CD leg or at the prior B or A points, taking partial profit along the way.

The appeal is that the pattern hands you a defined structure: a place to enter, a clear level where you are wrong, and logical targets. That built-in risk framing is why disciplined traders like them, regardless of how often they work.

Realistic caveats

Harmonic patterns look precise, and that precision can be misleading. A few honest points:

• The ratios rarely land perfectly. Real price seldom hits 0.786 on the nose, so traders allow tolerance zones. That subjectivity means two people can disagree on whether a pattern is valid.
• Identification is partly hindsight. A pattern is only certain once D has formed and price has turned. In real time you are betting a forming shape will complete, and many do not.
• They are probabilities, not predictions. A valid pattern marks a zone where a reversal is more plausible, not a certainty. Price can slice straight through D.
• Confirmation matters. Trading the raw D level without any confirming signal invites getting run over by a strong trend that ignores the pattern entirely.

Used well, harmonic patterns are a structured way to find reversal zones with clear risk. Used as a crystal ball, they will disappoint. They belong alongside trend context and confirmation, not in place of them. For the broader family of formations, see our overview of chart patterns, and to understand the ratios underneath, read our guide to Fibonacci retracement.

Finding harmonic setups without eyeballing every chart

Drawing and validating harmonic patterns by hand across many markets is tedious and easy to force, and the temptation to see a pattern that is not quite there is real. If you would rather spend your attention on confirming candidates than on measuring legs, TraderIndicator scans crypto, stocks and forex on TradingView and surfaces qualifying setups with an entry, a stop, and a documented reason attached, with signals that lock on candle close and do not repaint. It narrows the field so you can apply your own judgment to fewer, cleaner candidates.

This is education, not financial advice. Harmonic patterns describe historical price proportions and do not predict the future or guarantee a reversal. No pattern removes the risk of loss, so manage risk and do your own research.