Three stocks, BHEL, Gujarat Narmada Valley Fertilizers and Chemicals, and Manappuram Finance, are under futures and options (F&O) ban as their open interests rose above the prescribed percentage. Traders who deal in indices are not affected by the security ban, but open interest or market-wide position limits of any stock exceeding 95% of F&O prompts a ban which is lifted only when this percentage drops below 80%. The market-wide position limit for Delta Corp was 97.4% on Monday, while it stood at 92.6% and 89.6% for GNFC and Manappuram Finance, respectively.