Chart pattern · Reversal · Bullish
What is it, in one line
A gradual, curved reversal from a decline to an advance, without a sharp pivot.
Bullish · Reversal · verdict: Traditional claim, not yet measured here
A gradual, curved reversal from a decline to an advance, without a sharp pivot.
Method
Conventional target: No fixed formula; traditionally the prior decline sets a rough guide.
Invalidated by: A renewed low below the curve’s lowest point invalidates the pattern.
Like the inverse head and shoulders in skeleton — middle trough lowest — but WITHOUT the requirement that the outer two match, and with the descent and recovery required to be gradual: neither outer trough may stand more than maxBowlAtr above the middle.
The traditional claim
Read as a gradual bullish reversal.
How this detection is wrong
The shallowness cap is what separates a saucer from a V. Drop it and this becomes a superset of the inverse head and shoulders rather than a different shape.
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 |
| maxBowlAtr | bowl depth permitted, in ATR | 6 |
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.
Like the inverse head and shoulders in skeleton — middle trough lowest — but WITHOUT the requirement that the outer two match, and with the descent and recovery required to be gradual: neither outer trough may stand more than maxBowlAtr above the middle. 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 gradual bullish reversal.
The shallowness cap is what separates a saucer from a V. Drop it and this becomes a superset of the inverse head and shoulders rather than a different shape.
As an executable rule over open, high, low and close, with 7 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.