What is Key Delta Strike? Key Delta Strike is the strike with the largest net delta position for a stock. Why does Key Delta Strike matter? If this strike is below where the stock is currently trading it indicates there are large call positions in the stock. If the strike is above where the stock is trading it indicates there are large put positions in the stock. How to use Key Delta Strike This strike is considered a support or resistance line for the stock. Related articles What is Key Gamma Strike? What is SpotGamma Hedge Wall? What is Net Delta? What are Zero Gamma Levels? What is 25D Risk Reversal?