Harmonic Patterns: Gartley, Butterfly, Bat, and Crab

Trading the Hidden Geometry of Markets

Harmonic patterns are the advanced class of technical analysis. While basic patterns like head and shoulders rely on visual recognition, harmonic patterns use precise Fibonacci ratios to define their structure. A valid harmonic pattern is not just something that "looks right" — it must hit specific mathematical levels.

This precision makes harmonic patterns both harder to learn and more reliable when they appear. The Fibonacci ratios act as a quality filter, eliminating loose, ambiguous formations and leaving only setups where the math confirms the opportunity.

The Foundation: Fibonacci Ratios

Harmonic patterns are built on Fibonacci retracements and extensions:

• 0.382 — 38.2% retracement
• 0.500 — 50% retracement
• 0.618 — 61.8% retracement (the "golden ratio")
• 0.786 — 78.6% retracement
• 0.886 — 88.6% retracement
• 1.272 — 127.2% extension
• 1.618 — 161.8% extension
• 2.618 — 261.8% extension

Every harmonic pattern is defined by an XABCD structure — five points connected by four price swings (XA, AB, BC, CD). The ratios between these swings determine which pattern you are looking at.

The Gartley Pattern

The Gartley is the original harmonic pattern, developed by H.M. Gartley in 1935 and refined with Fibonacci levels by Scott Carney.

Bullish Gartley

• XA: The initial price move
• AB: Retraces 61.8% of XA
• BC: Retraces 38.2% to 88.6% of AB
• CD: Extends 127.2% to 161.8% of BC, and retraces 78.6% of XA
• Entry: Buy at point D
• Stop: Below X
• Target: 38.2% or 61.8% retracement of CD, or back to point A

The Gartley is a trend-continuation pattern. It appears during a pullback within an uptrend (bullish) or a bounce within a downtrend (bearish). Point D is where the pullback is expected to end and the trend to resume.

AAPL has formed numerous Gartley patterns during its long-term uptrend. The 78.6% retracement level of XA frequently acts as strong support where institutions accumulate.

The Butterfly Pattern

The Butterfly extends beyond the initial XA move, making it a pattern that catches reversals at new extremes.

Bullish Butterfly

• AB: Retraces 78.6% of XA
• BC: Retraces 38.2% to 88.6% of AB
• CD: Extends 161.8% to 261.8% of BC, and extends 127.2% to 161.8% of XA
• Entry: Buy at point D (which is below point X)
• Stop: Based on the 161.8% extension of XA
• Target: 38.2% to 61.8% retracement of CD

The Butterfly is powerful because point D pushes to new lows (bullish) or new highs (bearish) beyond the original X point. This flushes out stop-losses and triggers a reversal.

The Bat Pattern

The Bat pattern, discovered by Scott Carney, is known for its excellent risk-to-reward ratio.

Bullish Bat

• AB: Retraces 38.2% to 50% of XA
• BC: Retraces 38.2% to 88.6% of AB
• CD: Extends 161.8% to 261.8% of BC, and retraces 88.6% of XA
• Entry: Buy at point D
• Stop: Below X
• Target: 38.2% to 61.8% retracement of CD

The 88.6% retracement of XA makes the Bat pattern a deep pullback trade. The stop-loss below X is typically tight relative to the potential reward, giving you risk-to-reward ratios of 3:1 or better.

The Crab Pattern

The Crab produces the most extreme extension of the harmonic family and typically the largest measured moves.

Bullish Crab

• AB: Retraces 38.2% to 61.8% of XA
• BC: Retraces 38.2% to 88.6% of AB
• CD: Extends 224% to 361.8% of BC, and extends 161.8% of XA
• Entry: Buy at point D
• Stop: Based on the next Fibonacci level beyond D
• Target: Point C, then point A

The Crab extends 161.8% of XA, which means point D will be well beyond the original starting point. This extreme extension catches the most aggressive stop runs and often leads to powerful reversals.

How to Trade Harmonic Patterns

Step 1: Identify the Pattern

The hardest part is finding valid harmonic patterns. The Fibonacci ratios must be precise — a point D that retraces 82% of XA instead of 78.6% is not a valid Gartley. Use automated detection to handle the math.

Step 2: Wait for Point D Completion

The trade is placed at point D — the completion point. Do not enter early. Wait for price to reach the specific Fibonacci level that defines point D for your pattern.

Step 3: Look for Reversal Confirmation

At point D, look for:

• A candlestick reversal pattern (hammer, engulfing, pin bar)
• RSI oversold (bullish) or overbought (bearish)
• Volume spike indicating climactic selling or buying

Step 4: Enter with a Tight Stop

The beauty of harmonic patterns is the tight stop placement. Your stop goes just beyond point D (for a Gartley or Bat) or just beyond the relevant Fibonacci extension (for a Butterfly or Crab).

Step 5: Scale Out at Targets

• First target: 38.2% retracement of CD (conservative)
• Second target: 61.8% retracement of CD (standard)
• Third target: Point A (aggressive)

Harmonic Patterns in Practice: BTC and NVDA

BTC's large swings create clean Fibonacci retracements that produce valid harmonic patterns regularly. A Bat pattern on the 4-hour BTC chart with an 88.6% retracement of XA often coincides with major support/resistance levels, adding confluence.

NVDA forms harmonic patterns during its pullbacks within the broader AI-driven uptrend. Gartley patterns at the 78.6% retracement level of major swings have provided excellent entry points for trend continuation.

Why Automated Detection Matters

Manually checking Fibonacci ratios across five price points on thousands of charts is impractical. Our detection engine identifies valid harmonic patterns automatically, verifying that each point meets the precise Fibonacci requirements.

Scan for harmonic patterns now — our Premium tier includes all four harmonic pattern types with confidence scoring and Fibonacci level mapping.