Day traders' after-market lounge October 31, page-7

Blow off tops and bottom have high volume.

A meeting of two opposing forces.

On the way down, it's just one force with minimal resistance. When the buyers step in strongly, now there's two forces meeting. Both trying to override the other. But they don't override, they collide, pushing up volume and volatility to twice the size of normal.

Like when backwash meets an incoming wave.