The price of Brent crude oil (BZ=F) jumped as much as 4.3% to briefly cross $70 per barrel for the first time since September before paring gains. The gains add to a run-up over the past month that has seen oil rise roughly 15% as geopolitical risk premiums and record cold weather in the US have buoyed prices. "Oil markets are rapidly repricing geopolitical risk as the probability of direct US action against Iran rises," said Rystad Energy head of geopolitical analysis Jorge Léon. "The speed of the oil price reaction suggests markets see US military action against Iran as a real, near-term risk." On top of the geopolitical risk, the US crude market also saw an unexpected tightening last week.