The foreign institutional investors (FIIs) were net sellers to the tune of Rs 39.53 crore in the futures & option segment on Monday.According to data released on the NSE website, FIIs were net buyers of index futures to the tune of Rs 474.91 crore, and they bought index options worth Rs 26.63 crore. They were net sellers of stock futures to the tune of Rs 540.24 crore and they sold stock options worth Rs 0.83 crore.As per data available on the Sebi website - FIIs were net buyers of stocks worth Rs 249.10 crore in the spot market on the Friday. Domestic mutual funds (MFs) bought shares worth Rs 234.41 crore on the same day.