# Measured Move Detector Measured Move Detector is an indicator on [Vela](https://vela.luxalgo.com/chart), our next-generation charting platform, written in Pine Script®. Detects bullish and bearish AB=CD patterns from alternating confirmed swings, draws the legs, and projects the D completion at the classic 1.000 ratio with optional 1.272 and 1.618 extended variants plus a shaded BC extension zone. C must hold inside a 0.618-0.786 retracement of AB by default, and alerts fire when a pattern forms, when price reaches D, and on confirmed completion. - Indicator in the LuxAlgo Library, by LuxAlgo, published May 6, 2026. - Access: free. - Concepts: [ABCD](https://www.luxalgo.com/library/concept/abcd/) (primary) - Open on Vela: https://vela.luxalgo.com/chart?pineScriptCodeId=rp1nft092w7d5m63938lgdz4 - Page: https://www.luxalgo.com/library/indicator/abcd/ **Measured Move Detector** finds the simplest harmonic structure, known as the [AB=CD®](https://www.luxalgo.com/library/concept/abcd/), from confirmed swing points and projects its completion before price gets there. When alternating swings produce an A-B-C sequence whose C retracement lands inside the valid window, the build draws the legs, a dashed line at the classic completion where CD equals AB, and, optionally, dotted lines at the 1.272 and 1.618 extended variants plus a shaded BC extension zone. Completion is declared only when a confirmed swing lands within tolerance of a tracked ratio; the D label reports the matched ratio, full measurements in its tooltip. ## How to Trade with the Measured Move Detector? - **Projection in advance**: with A, B and C confirmed, the 1.000 line and the BC zone mark where a reaction is worth evaluating, and agreement between the two upgrades the level. - **D Reached vs Completed**: price touching the 1.000 projection is information, not a pattern. Completion requires the next confirmed swing to match a tracked ratio. - **Voids**: a move beyond point A, an overshoot past the furthest tracked ratio plus tolerance, or a second swing printing after the D candidate removes the structure. ## Measured Move Detector Settings - **Swing Length** (default 10): bars on each side confirming a swing; larger values find bigger, later patterns. - **C Retracement Min** (default 0.618): lower bound of the valid C retracement of AB. - **C Retracement Max** (default 0.786): upper bound; C may never exceed A. - **Completion Ratio Tolerance** (default 0.05): accepted CD-to-AB deviation. 0.95 to 1.05 times AB completes the classic form. - **Extended Variants (1.272 and 1.618)** (default on): also project and match the extended completions. - **BC Extension Zone (1.272 to 1.618)** (default on): shade the second way of projecting D. - Style: **Leg Line Width** (default 2) and **Point Labels (A, B, C)** (default on); the D label always shows. ## Frequently Asked Questions ### How does the Measured Move Detector relate to five-point patterns like the Crab? The AB=CD is the engine inside most of them: larger harmonic definitions generally expect an equivalent or extended ABCD finishing at their own D point. A five-point pattern like the [Crab®](https://www.luxalgo.com/library/concept/crab/) adds the X leg and a stricter ratio set; this build isolates the reusable core. ### Why did a forming pattern disappear? It was voided: price broke beyond A, overshot the furthest tracked completion by more than the tolerance, or another swing confirmed after the D candidate. A violated ABCD is dropped, not renegotiated. ### Which alerts does the build provide? Three per side: Forming when C confirms inside the retracement window, D Reached when price first touches the 1.000 projection, and Completed when a confirmed swing matches a tracked ratio. --- Bat®, Crab®, Shark®, AB=CD® and 5-0® are registered trademarks of their owner, used here only to identify the patterns. LuxAlgo's tools are independent implementations and are not affiliated with or endorsed by the trademark owner. ## Related indicators - [Cypher](https://www.luxalgo.com/library/indicator/cypher/) (Elliott & Harmonics): markdown at https://www.luxalgo.com/library/indicator/cypher.md - [Harmonic Pattern Detection](https://www.luxalgo.com/library/indicator/harmonic-pattern-detection/) (Harmonic Patterns): markdown at https://www.luxalgo.com/library/indicator/harmonic-pattern-detection.md - [Half-Retracement Reversal Detector](https://www.luxalgo.com/library/indicator/5-0/) (5-0): markdown at https://www.luxalgo.com/library/indicator/5-0.md - [Three Drive Pattern Detector](https://www.luxalgo.com/library/indicator/three-drive-pattern-detector/) (Three Drives): markdown at https://www.luxalgo.com/library/indicator/three-drive-pattern-detector.md - [Potential Reversal Zone](https://www.luxalgo.com/library/indicator/potential-reversal-zone/) (Elliott & Harmonics): markdown at https://www.luxalgo.com/library/indicator/potential-reversal-zone.md - [Anti-patterns](https://www.luxalgo.com/library/indicator/anti-patterns/) (Elliott & Harmonics): markdown at https://www.luxalgo.com/library/indicator/anti-patterns.md - [RSI BAMM](https://www.luxalgo.com/library/indicator/rsi-bamm/) (Elliott & Harmonics): markdown at https://www.luxalgo.com/library/indicator/rsi-bamm.md - [Overextension Reversal Detector](https://www.luxalgo.com/library/indicator/shark/) (Shark): markdown at https://www.luxalgo.com/library/indicator/shark.md --- Source: https://www.luxalgo.com/library/indicator/abcd/ (LuxAlgo Library). Free to use with attribution: https://www.luxalgo.com/library/license/