Trading volumes from retail, institutional and proprietary, traders in equity futures and options segment are likely to fall sharply due to the new measures announced by the Securities and Exchange Board Tuesday, according to a few traders and analysts. While the restriction of weekly index options to one benchmark index per exchange from Nov. 20 will lead to lower volumes from retail futures and options traders, the four-times-a-day intraday position monitoring by exchanges is seen to cool down large amount of orders generated from algorithms by foreign portfolio investors and proprietary traders on the expiry day.