The document provides a summary of derivative trading activity in India for July 15, 2010. Key points include: - The Nifty futures open interest increased slightly while the Minifity interest decreased. Premiums on the Nifty July and August futures changed. - A few stocks saw increases in open interest like DCHL, GESHIP, and RNRL, while others like ASIANPAINT, EXIDEIND, and SUNTV saw decreases. - The put-call ratio for Nifty increased slightly. Implied volatility for at-the-money options rose as well. - Some trading strategies involving stocks like RELIANCE, TATASTEEL, R