Oil posted the biggest weekly gain since late September as Saudi Arabia’s plan to slice output spurred a surge in physical crude buying. Futures in New York advanced $3.72 this week and Brent oil topped $55 a barrel for the first time since February. Saudi Arabia’s pledge earlier this week to cut production by 1 million barrels a day in February and March has made for a tighter supply outlook sooner than anticipated. Meanwhile, prospects for additional stimulus under a Biden administration spurred broader market gains. Saudi Arabia’s surprise cut appears to have caught some Asian buyers by surprise and demand for U.S. crude for export to Asia has gained this week. Unipec, the trading arm of China’s largest refiner, bought its eighth cargo […]