A gamma wall is a strike price with a very large concentration of options open interest, where dealer hedging activity clusters. Because dealers hedge heavily around that strike, it tends to act as strong support or resistance — a level price struggles to break (gamma exposure).

Why they form

When enormous open interest sits at one strike, dealers who are short those options must hedge intensely as price approaches it. In a positive-gamma regime, that hedging opposes price movement toward the strike — selling as price rises into it, buying as it falls toward it — which pins price near the wall (pinning and max pain).

How they behave

A call wall above price often caps rallies (resistance); a put wall below often cushions declines (support). Price can spend a whole session trapped between them, drawn toward the largest strike — the "max pain" pin. These walls are most powerful on expiration days, when the open interest is about to settle (theta vs gamma at expiration).

A gamma wall isn't a line someone drew on a chart. It's where thousands of contracts force dealers to lean against price — a level with real money behind it.

When walls break

Walls hold in positive gamma and crumble in negative gamma, where hedging flips to amplify moves — a break through a wall can then accelerate violently as dealers chase (positive vs negative gamma). Reading where the walls sit is part of the dealer-positioning picture Analyst tracks. See the gamma flip.