The Foreign Institutional Investors (FIIs) were net buyers to the tune of Rs 949.26 crore in the futures & option segment on Thursday.According to data released by the NSE, FIIs were net buyers of index futures to the tune of Rs 381.27 crore while sold index options worth Rs 165.89 crore. They were net buyers of stock futures to the tune of Rs 731.41 crore and bought stock options worth Rs 2.47 crore.As per data available on the Sebi website - FIIs were net sellers of stocks worth Rs 668.10 crore in the cash market on Wednesday. Mutual funds were net sellers of shares worth Rs 16.50 crore on the same day.