The flow of crude through the Strait of Hormuz is creeping higher as producers across the Middle East boost exports in the face of Iran's lingering threat to shipping. The increase is keeping global crude oil prices in check. About 6 million to 8 million barrels a day of crude are now being shipped through the world's key oil chokepoint, according to estimates from oil traders involved in and monitoring cargo activity.

Flows slipped in July, when an onslaught of attacks on supertankers by Iran led to the breakdown of an interim ceasefire and heightened risks to navigation. They remain at roughly half prewar levels.