Harmonic Pattern Detection, Prediction, and Backtesting ToolOverview:
The ultimate harmonic XABCD pattern identification, prediction, and backtesting system.
Harmonic patterns are among the most accurate of trading signals, yet they're widely underutilized because they can be difficult to spot and tedious to validate. If you've ever come across a pattern and struggled with questions like "are these retracement ratios close enough to the harmonic ratios?" or "what are the Potential Reversal levels and are they confluent with point D?", then this tool is your new best friend. Or, if you've never traded harmonic patterns before, maybe it's time to start. Put away your drawing tools and calculators, relax, and let this indicator do the heavy lifting for you.
- Identification -
An exhaustive search across multiple pivot lengths ensures that even the sneakiest harmonic patterns are identified. Each pattern is evaluated and assigned a score, making it easy to differentiate weak patterns from strong ones. Tooltips under the pattern labels show a detailed breakdown of the pattern's score and retracement ratios (see the Scoring section below for details).
- Prediction -
After a pattern is identified, paths to potential targets are drawn, and Potential Reversal Zone (PRZ) levels are plotted based on the retracement ratios of the harmonic pattern. Targets are customizable by pattern type (e.g. you can specify one set of targets for a Gartley and another for a Bat, etc).
- Backtesting -
A table shows the results of all the patterns found in the chart. Change your target, stop-loss, and % error inputs and observe how it affects your success rate.
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// Scoring
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A percentage-based score is calculated from four components:
(1) Retracement % Accuracy - this measures how closely the pattern's retracement ratios match the theoretical values (fibs) defined for a given harmonic pattern. You can change the "Allowed fib ratio error %" in Settings to be more or less inclusive.
(2) PRZ Level Confluence - Potential Reversal Zone levels are projected from retracements of the XA and BC legs. The PRZ Level Confluence component measures the closeness of the closest XA and BC retracement levels, relative to the total height of the PRZ.
(3) Point D / PRZ Confluence - this measures the closeness of point D to either of the closest two PRZ levels (identified in the PRZ Level Confluence component above), relative to the total height of the PRZ. In theory, the closer together these levels are, the higher the probability of a reversal.
(4) Leg Length Symmetry - this measures the ΔX symmetry of each leg. You can change the "Allowed leg length asymmetry %" in settings to be more or less inclusive.
So, a score of 100% would mean that (1) all leg retracements match the theoretical fib ratios exactly (to 16 decimal places), (2) the closest XA and BC PRZ levels are exactly the same, (3) point D is exactly at the confluent PRZ level, and (4) all legs are exactly the same number of bars. While this is theoretically possible, you have better odds of getting struck by lightning twice on a sunny day.
Calculation weights of all four components can be changed in Settings.
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// Targets
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A hard-coded set of targets are available to choose from, and can be applied to each pattern type individually:
(1) .618 XA = .618 retracement of leg XA, measured from point D
(2) 1.272 XA = 1.272 retracement of leg XA, measured from point D
(3) 1.618 XA = 1.618 retracement of leg XA, measured from point D
(4) .618 CD = .618 retracement of leg CD, measured from point D
(5) 1.272 CD = 1.272 retracement of leg CD, measured from point D
(6) 1.618 CD = 1.618 retracement of leg CD, measured from point D
(7) A = point A
(8) B = point B
(9) C = point C
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// Stops
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Stop-loss levels are also user-defined, in one of three ways:
(1) % beyond the furthest PRZ level (below the PRZ level for bullish patterns, and above for bearish)
(2) % beyond point D
(3) % of distance to Target 1, beyond point D. This method allows for a proper Risk:Reward approach by defining your potential losses as a percentage of the potential gains. This is the default.
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// Results Table / Backtesting Statistics
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To properly assess the effectiveness of a specific pattern type, a time limit is enforced for a completed pattern to reach the targets or the stop level. When this time limit expires, the pattern has "timed out", and is no longer considered in the Success Rate statistics. During the time limit period, if price reaches Target 1 before reaching the Stop level, the pattern is considered successful. Conversely, if price reaches the Stop level before reaching Target 1, the pattern is considered a failure. The time limit can be changed in Settings, and is defined in terms of the total pattern length (point X to point D). It is set to 1.5 by default.
Increasing the time limit value will give you more realistic Success Rate values, but will less accurately represent the success rate of the harmonic patterns (i.e. the more time that elapses after a pattern completes, the less likely it is that the price action is related to that pattern).
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// Coming soon...
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I have a handful of other features in development, including:
(1) Drawing incomplete patterns as they develop. This will allow you more time to plan entries and stops, or potentially trade reversals from point C to point D PRZ levels.
(2) Support for the Shark and Cypher patterns
(3) Alerts
Please report any bugs, runtime errors, other issues or enhancement suggestions.
I also welcome any feedback from experienced harmonic pattern traders, especially regarding your strategy for setting targets and stop-losses.
@reees
Indikator Pine Script®






















