The number of financial bets on crude oil prices hitting $200 a barrel before the end of this year has almost doubled in the last month, a further sign of growing concern that oil prices will continue to rise sharply in the near term.

The strong buying of these call options – contracts that give holders the right to buy crude oil at a predetermined price and date – comes as spot oil prices in London on Thursday hit a fresh record high around the $146 a barrel level.