Pattern Detail

AB=CD

The building block of every harmonic pattern: two equal-length legs around a partial retracement.

A B C D
  • C = 0.618-0.786 retrace of AB
  • CD = AB (equal legs)
Idealized bullish AB=CD. It completes at a low and projects a move up.

Bullish AB=CD

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How to read this

Everything here is in R, the setup's own risk. 1R is the distance from the entry (the pattern's closing price) to where it would be proven wrong — its lowest low over the 4 bars that form it. So "offered 2R" means price ran twice that distance in your favor at some point before the stop. It does not assume you took profit there: a target is a strategy choice.

Room offered (≥ 1R)

43.4%

Not reliable

Offered at least 1× its risk before the stop, vs 44.1% for a random long entry (-0.7 pts).

Move size vs normal

1.07×

Realized range over the next 20 bars vs a random bar. About normal.

Typical room (20-bar)

1.13R

Average run in favor (capped at 3R), vs 1.16R for a random long entry.

Summary

Offered ≥1R 43.4% of the time vs 44.1% for a random long entry. The 0.7-point gap is no bigger than the ±8.1-point margin of error you would get by chance from 145 occurrences. Not a reliable edge.

Room offered, this setup vs a random long entry

Outcome This setup Random entry Edge
Offered ≥ 1R 43.4% 44.1% -0.7
Offered ≥ 2R 24.1% 24.7% -0.5
Offered ≥ 3R 17.2% 15.7% +1.6
Stopped < 1R 35.9% 42.7% -6.8
Went sideways 20.7% 13.2% +7.5

145 occurrences · 10,656 random-entry controls · 20-bar horizon

Bearish AB=CD

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How to read this

Everything here is in R, the setup's own risk. 1R is the distance from the entry (the pattern's closing price) to where it would be proven wrong — its highest high over the 4 bars that form it. So "offered 2R" means price ran twice that distance in your favor at some point before the stop. It does not assume you took profit there: a target is a strategy choice.

Room offered (≥ 1R)

41.9%

Not reliable

Offered at least 1× its risk before the stop, vs 43.0% for a random short entry (-1.2 pts).

Move size vs normal

0.97×

Realized range over the next 20 bars vs a random bar. About normal.

Typical room (20-bar)

1.17R

Average run in favor (capped at 3R), vs 1.16R for a random short entry.

Summary

Offered ≥1R 41.9% of the time vs 43.0% for a random short entry. The 1.2-point gap is no bigger than the ±7.7-point margin of error you would get by chance from 160 occurrences. Not a reliable edge.

Room offered, this setup vs a random short entry

Outcome This setup Random entry Edge
Offered ≥ 1R 41.9% 43.0% -1.2
Offered ≥ 2R 25.0% 25.9% -0.9
Offered ≥ 3R 20.0% 17.0% +3.0
Stopped < 1R 45.6% 47.1% -1.5
Went sideways 12.5% 9.9% +2.6

160 occurrences · 10,573 random-entry controls · 20-bar horizon

AB=CD is the simplest harmonic structure and the building block the others are made from. It is four points, A to B to C to D, defined by two legs of equal length around a partial retracement. The signature is the symmetry: the C-to-D leg matches the A-to-B leg in length.

How to spot it

  • A first leg from A to B, then a partial retracement from B to C against it.
  • B to C retraces 0.618 to 0.786 of AB, a measured pullback rather than a full reversal.
  • A final leg from C to D that matches AB in length, so the move covers the same ground twice.
  • The structure completes at D, a swing low in an uptrend (a buy) or a swing high in a downtrend (a sell).

The chart above marks the A, B, C, D points on a real occurrence, with the ratio of each leg.

Why it matters

The idea is symmetry. If the market moved a certain distance from A to B, paused, and then resumed, the second leg often travels a similar distance before stalling. D is the point of equality, where the move has covered the same ground twice and is read as complete, so the structure looks for a pause or a turn there. The stop sits just beyond D, which keeps it close.

That simplicity is also the catch. Two equal legs happen all the time without marking anything significant, so without context the AB=CD fires on a lot of meaningless structure. It is the most common pattern in the family, and the higher frequency is exactly what makes it useful for seeing how a high-volume setup behaves over a long sample.

The honest question is not whether the shape can be drawn on a chart, it always can after the fact, but whether a completion actually leads anywhere. That is what the data below measures.

Does it actually work?

A pattern is a setup, not a trade, so the question is not “did it win” but “how much room did the move offer before the structure was proven wrong.” The tabs below answer that across five futures markets (Nasdaq, S&P 500, gold, crude oil, natural gas) and seven timeframes from one minute to one day.

For each completion we measure the room price offered in units of the pattern’s own risk, then set it against what a random swing pivot of the same kind would have done. A AB=CD that turns up from a swing low is judged against ordinary swing lows; one that turns down from a swing high, against ordinary swing highs. When the completion offers more room more often than those random swings, that shows up as a real edge. When it does not, the page says so plainly.

Harmonic structures are rare, so read the sample size in view. On the slower timeframes a AB=CD completes only single digits of times, or not at all, while the faster timeframes give a larger sample. Thin samples are flagged for you.

How we measured it

  • Entry is the close of the bar that confirms the D point, the earliest a trader could act without hindsight.
  • One unit of risk, 1R, is the distance from that close to D itself, the swing extreme the structure completes at. A move back through D says the pattern has failed.
  • We follow the next 20 bars and record how far price ran in your favor, in multiples of that risk, before D gave way.
  • The comparison is a random swing pivot of the same side, which already sits at a turning point with a tight stop. That keeps it apples-to-apples: the question is whether a AB=CD swing runs further than an ordinary swing of the same shape, not whether a tight stop flatters the numbers.

What this page does not cover

  • A profit target. Harmonic tradition puts one at a Fibonacci retracement, but where you take profit is a strategy choice, so this measures only the room the structure tends to offer.
  • A trend filter, or confluence with support, resistance, or a higher-timeframe level, which traders normally use to weight a completion.
  • A guarantee. A valid shape on the chart is a setup, not a certainty. What it tends to do next is exactly what the numbers above describe.

FAQ

Does the AB=CD pattern actually work?

Harmonic patterns are described everywhere but rarely tested honestly. This page scores every completed AB=CD by the room it offered in units of its own risk, measured against random swing pivots of the same kind, and counts a pattern only on the bar its final pivot confirms, so nothing is read in hindsight. The result is a like-for-like comparison rather than the round-number success rates usually quoted for harmonics.

What is the AB=CD pattern success rate?

There is no single reliable figure, and the round-number rates repeated online rarely specify instrument, timeframe, or test period, and almost never state what target and stop they assume. Rather than quote folklore, this page measures how far a completion runs in units of its own risk and whether that beats an ordinary swing of the same shape. The tabs show that comparison across five markets and seven timeframes.

How is the AB=CD defined here?

It is a four-point structure where B to C retraces 0.618 to 0.786 of AB, and the C-to-D leg matches AB in length, both holding at once within a 5% tolerance. D is the point of equality, where the move has covered the same ground twice. Pivots use 3 bars on each side and are confirmed before they count.

Sample AB=CD Completions (20)

Based on data through Apr 29, 2026

Time Direction Risk (pts) Room offered Result
Mar 24, 2026 Bullish 116 1.17R Ran ≥1R
Jul 11, 2025 Bullish 123.75 0.28R Flat
Jun 9, 2025 Bearish 66.25 0.16R Stopped
Mar 21, 2025 Bearish 32 0.00R Stopped
Jan 16, 2025 Bullish 85.25 0.57R Stopped
Dec 3, 2024 Bearish 60 0.21R Stopped
Nov 11, 2024 Bullish 71.25 1.15R Ran ≥1R
Oct 7, 2024 Bearish 95 2.01R Ran ≥1R
Sep 10, 2024 Bearish 41 3.00R Ran ≥1R
Aug 22, 2024 Bearish 109 3.00R Ran ≥1R
Jul 29, 2024 Bearish 155.25 0.70R Flat
Jun 6, 2024 Bullish 48.75 0.18R Stopped
May 13, 2024 Bullish 49.25 1.76R Ran ≥1R
Apr 18, 2024 Bullish 11.75 3.00R Ran ≥1R
Apr 11, 2024 Bearish 18 0.00R Stopped
Mar 11, 2024 Bearish 43.25 0.79R Stopped
Feb 12, 2024 Bearish 44.75 3.00R Ran ≥1R
Feb 1, 2024 Bearish 59.75 0.02R Stopped
Jan 23, 2024 Bullish 55.75 1.03R Ran ≥1R
Jan 3, 2024 Bullish 46.25 0.63R Stopped

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