Supply & demand
Ademand zoneis where a sharp rally began — buyers overwhelmed sellers there, and price often returns to it before continuing up. Asupply zoneis the opposite.
Wyckoffadds the ستۆری: accumulation (smart money buying quietly) → spring (final stop-hunt low) → markup (the rally). Recognizing accumulation/distribution helps you enter before the crowd. This is School 3 in the ShaFX signal engine.