What is Top Put OI (Open Interest)? Top Put OI (Open Interest) is the options strike with the largest number of put options. Why does Top Put OI (Open Interest) matter? This dynamic can cause stocks to pin a level or create support for the underlying stock. How to use Top Put OI (Open Interest) Consider it as a downside target or support area when trading the stock. Interested in learning more? Related articles What is Gamma in Next Expiration? What is Delta in Next Expiration? What is Total Call OI (Open Interest)? What is SpotGamma Hedge Wall? What are Total Calls?