The Foreign Institutional Investors (FIIs) were net buyers to the tune of Rs 1,006.98 crore in the futures & option segment on Monday.According to data released by the NSE, FIIs were net buyers of index futures to the tune of Rs 843.34 crore and bought index options worth Rs 238.50 crore. They were net sellers of stock futures to the tune of Rs 95.55 crore while bought stock options worth Rs 20.69 crore.As per data available on the Sebi website - FIIs were net buyers of stocks worth Rs 3,179.30 crore in the cash market on Friday. Mutual funds were net buyers of shares worth Rs 25.80 crore on the same day.