New Delhi, Sept. 29 -- The Nifty 50 registered its worst performance, as the index's September series was its worst September monthly performance in the last 25 years, dragged down by a surge in crude oil prices, higher bond yields, and persistent selling by overseas investors.

The index finished its monthly series with a drop of 6.3%, marking the worst September series since 2001, when it dropped 13.53%.

September proved difficult across most sectors. Pharma was the only sector to finish the series with gains, while auto, realty, and PSU banking stocks were the worst performers during the period. Small-cap and mid-cap indices also snapped a five-series winning run.

The weakness was further reflected in the Nifty 50's weekly performanc...