Chart pattern · Reversal · Bullish
What is it, in one line
Two troughs at roughly the same level, separated by a moderate peak.
Bullish · Reversal · verdict: Traditional claim, not yet measured here
Two troughs at roughly the same level, separated by a moderate peak.
Method
Conventional target: A break above the peak projects a rise equal to the trough-to-peak distance.
Invalidated by: A close back below either trough invalidates the pattern.
The two most recent confirmed swing lows sit within a tolerance band of one another, and the swing high between them stands at least minSepAtr above both.
The traditional claim
Read as a bullish reversal once price closes above the peak between the two troughs.
How this detection is wrong
Same as the double top inverted: without the peak-height floor this fires on any flat base.
Published so the count can be reproduced. Every figure below is a parameter of the rule, not a preference: change one and the occurrence count changes with it.
| Parameter | Meaning | Default |
|---|---|---|
| pivotLeft | bars to the left of a swing | 3 |
| pivotRight | bars to the right before a swing is confirmed | 3 |
| lookback | bars searched for the swings | 120 |
| atrPeriod | bars of ATR used to size everything below | 14 |
| flatTol | how level two points must be | 0.02 |
| minSepAtr | separation required between swings, in ATR | 1 |
These share enough geometry that a detector can return more than one of them on the same bar. The engine reports every match rather than picking a winner.
Every pair on the site that can be mistaken for another, and what separates each: the look-alikes index.
The two most recent confirmed swing lows sit within a tolerance band of one another, and the swing high between them stands at least minSepAtr above both. The detector also requires a prior downtrend, so the same shape in the wrong context is not counted.
It is read as bullish. Read as a bullish reversal once price closes above the peak between the two troughs.
Same as the double top inverted: without the peak-height floor this fires on any flat base.
As an executable rule over open, high, low and close, with 6 named parameters — including bars to the left of a swing 3, bars to the right before a swing is confirmed 3, bars searched for the swings 120 — all published on this page so the count can be reproduced. Strict and loose variants are defined as well, so the sensitivity of the count to those thresholds is visible rather than assumed.
Measurement pending re-run
No hit rate is published here yet. The run that would supply one was computed on engine ca6d9e36c81c; the engine is now cfb08765de7c. Its candlestick rows included the still-forming bar, and it predates the chart formations entirely, so those figures have been withdrawn rather than published with a caveat. The definition above is unaffected: it is what the detector tests, and no re-run changes it.
Same shape, opposite reading
The shapes are close, and the prior trend is what decides which one fired: this rule requires a preceding downtrend, its mirror a preceding uptrend.
Double Top: Two peaks at approximately the same level, separated by a trough.