Reading GEX levels: walls & key strikes
Call walls, put walls, and the strikes price gravitates to.
A GEX chart plots dealer gamma by strike. The tallest bars are the strikes with the most hedging pressure, and they act like magnets and barriers for price. The call wall is the largest call gamma strike at or above spot; the put wall is the largest put gamma strike at or below spot.
Call walls and put walls
- Call wall — the strike with the largest positive gamma, usually above price. It tends to act as resistance: dealer hedging sells into rallies toward it.
- Put wall — the strike with the largest (often negative) gamma below price. It tends to act as support — until it breaks, at which point hedging can accelerate the move.
Magnets near expiry
The closer to expiry, the stronger these strikes pull — this is the OPEX pinning effect. Large-OI strikes become price magnets as gamma concentrates into the final hours.Using the levels
Treat the call wall and put wall as a probable range for the session in a positive-gamma regime. Fades toward the walls have the odds; a decisive break of a wall is a signal the regime may be shifting.