Indian traders are growing wary, with the Nifty’s rollover cost sinking to a five-month low at the expiry of the October series as high oil prices and the threat of renewed US-Iran hostilities dull their appetite for fresh bets. The cost fell to 0.29% in October from 0.78% at the end of the September series, according to an Aditya Birla Money Ltd report. It was the lowest since the May expiry, when traders were similarly worried about a fragile ceasefire in West Asia, said Shai Coelho, founder of online analytics platform Vtrender.