The document provides a summary of derivative market activity in India as of September 13, 2010. Key points include: - Open interest in Nifty and Mini Nifty futures increased between 3-5% as the markets closed at 5640.05. - Nifty September futures closed at a discount of 8.20 points while October futures closed at a discount of 3.15 points. - Total open interest in the market was Rs. 1,90,183 crore with stock futures open interest at Rs. 50,452 crore. - Voltas, Ashok Leyland, and BankIndia saw open interest increases over 15% while Opto Circuits, Ultratech C