Wyckoff trading method, page-1853

RXP nose dived today on the announcement of a substantial holder reducing their position.
It makes me wonder why a gap up was allowed to happen on the 21st in the first place.
Not to sure what to make of it at present, so will remain on the sidelines.
I'm really curious to see if we have a 2day shakeout which would confirm the strength in the background.