The Foreign institutional investors (FIIs) were net buyers of Rs 1,898.64 crore in the futures & options segment on Wednesday.According to data released by the NSE, FIIs were net buyers of index futures to the tune of Rs 1,386.07 crore and bought index options worth Rs 287.57 crore. They were net buyers of stock futures to the tune of Rs 200.50 crore and bought stock options worth Rs 24.50 crore.