Oil swung in a turbulent session amid speculation the US may join the West Asia conflict, with traders focused on flows through the region’s vital shipping chokepoint. Brent crude futures edged up 3 cents to $76.5 a barrel at noon in the US. Earlier in the session, prices were down around 2% a day after jumping over 4%. The oil market’s main concerns are flows from Iran and the threat to vessel traffic in the Strait of Hormuz, through which about a quarter of the world’s crude shipments flow.