RE-ENTRY / S&P 500
A return is part of the story.
A brief re-entry and the final close answer different questions.
86.8%1.5σ excursions that re-entered
41.4%1.5σ touch days closing inside
In the S&P 500 study, 86.8% of individual excursions beyond 1.5σ returned inside the band. Separately, 41.4% of sessions touching a 1.5σ boundary finished inside that band pair. A session can contain several excursions.
READING THE FINDING
The denominators differ. An excursion is a contiguous episode with minute closes outside the band; a touch day is identified using minute highs and lows. A temporary return does not establish a lasting reversal or a profitable trade.