Nifty futures dropped 1.5%, dragging down spot indexes, which several dealers attributed to a trading mistake, though no details were immediately available.
A National Stock Exchange official told Reuters the exchange was looking into the matter, though they would not confirm whether the sudden drop in the futures index was due to a trading mistake.
Charts showed volumes in the Nifty spiked at 2:26 p.m. India time, sparking sharp falls in the futures index.
