What is the Gamma Pinning Effect? This is when a stock is drawn to a specific price as it nears expiration. Technically, when approaching an expiry and when close to an options strike, the increase in gamma creates dealer hedging activity which causes the stock to gravitate back to the strike as the dealer stock hedging volume is relatively large compared to other flows. Interested in learning more? Related articles What is Highest Gamma Expiration Date? What is Highest Delta Expiration Date? What is Gamma Flip? What is a Gamma Profile? What is Volatility Trigger™?