Hedge funds and money managers have upped their bearish bets on on US oil fourfold in the past month as demand concerns return to markets, according to a report by Bloomberg citing data from the Commodity Futures Trading Commission (CFTC).

CFTC data shows that during the week ended 7 November, short-only positions increased by more than 20,000 contracts to 95,756 and shorts bets are now at the highest level seen since July.

At the same time, hedge funds slashed wagers on rising prices for the sixth straight week. US crude ended last week near July lows, before rebounding slightly on Monday.