Call Walls, Put Walls, and Zero Gamma Explained

What Are Structural Levels?

Structural levels are specific price points where options market maker hedging creates measurable pressure on the underlying stock. Unlike traditional support and resistance based on chart patterns, structural levels are calculated from real options positioning data.

The three most important levels are the Call Wall, the Put Wall, and the Zero Gamma line. Together, they define the "playing field" — the range where price is likely to stay, and the boundaries beyond which behavior changes dramatically.

The Call Wall: The Ceiling

The call wall is the strike price with the highest positive gamma exposure from call options. It's where the densest concentration of call open interest creates the strongest stabilizing force.

As price approaches the call wall from below, market makers who are long call gamma begin selling stock to delta-hedge. This selling pressure creates resistance — a ceiling that price struggles to push through.

The call wall isn't unbreakable. Strong buying pressure, catalysts, or a shift in positioning can push price through. But when it holds, it defines the upper boundary of the current range.

In GammaLens, the call wall is marked with a green "CW" label in both the Options Matrix and the Gamma Profile chart.

The Put Wall: The Floor

The put wall is the mirror image — the strike with the highest positive gamma exposure from put options. It's where massive put open interest creates buying pressure.

As price drops toward the put wall, dealers who are long put gamma buy stock to hedge. This buying pressure creates support — a floor that catches selloffs.

Put walls are particularly important during selloffs. They're often the levels where seemingly relentless selling suddenly stops and price bounces. The bounce isn't random — it's dealers absorbing selling pressure through forced hedging.

The put wall appears with a red "PW" label in GammaLens.

Zero Gamma: The Volatility Trigger

The zero gamma line is where net gamma exposure flips from positive to negative. Above this line, dealer hedging stabilizes price. Below it, dealer hedging amplifies moves.

This makes the zero gamma line a critical threshold. When price crosses below zero gamma, the market transitions from a stabilizing regime to a destabilizing one. Moves get bigger. Intraday swings widen. Trends accelerate.

Think of zero gamma as the volatility switch. Above it: calm, range-bound, mean-reverting. Below it: trending, volatile, momentum-driven.

Traders use zero gamma as a regime indicator — it changes how you should trade. In a positive gamma regime, fading extremes works. In negative gamma, riding momentum works.

Using All Three Levels Together

The three levels together define the complete structural picture:

Call Wall (CW) = ceiling. Price is likely to stall or reverse here. Put Wall (PW) = floor. Price is likely to bounce here. Zero Gamma (ZG) = regime switch. Behavior changes when price crosses this level.

The range between PW and CW is the "expected range" — where price is most likely to trade. The position of spot price relative to zero gamma tells you the current regime.

Spot above ZG with room to CW = bullish, stable. Buy dips, sell rips. Spot below ZG moving toward PW = bearish, volatile. Momentum trades work. Spot at CW or PW = watch for a breakout or rejection — this is where the next move starts.

These levels update as the options chain changes throughout the day.