The Strait of Hormuz has remained largely blocked since the Iran war began in late February and has been subject to an international diplomatic arm wrestle ever since. | REUTERS

The number of supertankers hauling unsanctioned oil through the Strait of Hormuz has shown signs of rising in recent days, offering limited relief to an oil market that’s suffered the largest supply disruption in history.

Four ships each hauling 2 million barrels of mostly-Iraqi crude have exited since May 10 — a rate close to 2 million barrels a day — according to vessel tracking data compiled by Bloomberg. Still, prior to the war, there were about 20 or so tankers of various sizes crossing the waterway daily.

Oil traders are monitoring Hormuz flows closely because the blockage of the waterway has already cut about a billion barrels from global supply.…