What is a Call Wall? The Call Wall is the strike with the largest net positive Gamma in the underlying stock/ETF. Why does Call Wall matter? It can act as resistance, indicating where sellers may enter the market. How to use a Call Wall The Call Wall level lets you know where support lies for a stock, and a change in the price of the Call Wall can help you can manage your risk while either long or short. A shift higher is often a bullish signal while a shift lower in the Call Wall is a bearish signal. Related articles What is Call Wall Strike? What is a Put Wall? What is a Gamma Profile? What is Put Wall Support? What is Key Gamma Strike?