Strait of Hormuz oil flows are running above market estimates of 4 million barrels a day, people with knowledge of the shipments say, as a covert shuttle trade keeps global crude prices well below the worst-case scenarios feared when the Iran war began.
Tankers are crossing the world’s busiest energy chokepoint with their transponders switched off, transferring cargoes onto waiting vessels in the Gulf of Oman before sailing on to buyers across Asia and beyond.
The volumes surpass what most traders had assumed, the people said, speaking anonymously because of the sensitivity of the matter. They did not specify by how much.
How Strait of Hormuz oil flows are holding global prices down
US Energy Secretary Chris Wright said last week that 9 million barrels a day crossed Hormuz in the preceding seven days, a figure that surprised many traders and sits at almost half of pre-war rates.
Brent futures have spent much of August between $80 and $90 a barrel as a result, far below the $150 some analysts had braced for when the conflict broke out.
According to the Congressional Research Service, approximately 25% of global oil supply (around 20 million barrels a day of crude and petroleum products) moved through Hormuz during 2025, underscoring how much is now being rerouted or withheld compared with pre-war norms.
The dark shuttle trade has combined with pipeline workarounds, stockpile releases and softer global demand to limit the economic damage from the war, traders and analysts say.
Satellite data compiled by Transport Topics recorded 12 ship-to-ship oil transfers off Oman on 10 August alone, an indication of how consistently tankers are moving cargo through the strait despite the attacks.
Around 150 ships (from giant oil tankers to bulk commodity carriers) are currently floating off the Omani coast waiting for transfers, compared with roughly 40 in January, according to data from the European Union’s Sentinel 1 satellite.
ADNOC attacks and Saudi Arabia’s tentative shift
23 vessels belonging to Abu Dhabi National Oil Company (ADNOC) have been attacked while transiting Hormuz since the conflict began, resulting in one fatality and 20 injuries to crew members, the company said.
‘Despite the repeated targeting of our vessels, we are determined to continue meeting our responsibility to safely deliver energy to global markets,’ ADNOC said in a statement.
‘An attack on the infrastructure that keeps energy flowing is not simply an attack on a company,’ it added. ‘The disruption in the Strait of Hormuz is inflicting profound damage far beyond those directly impacted in this region.’
ADNOC has already sold about 135 million barrels of crude to buyers worldwide and issued another round of sales last week, according to people with knowledge of the UAE’s shipments, who said there was little sign of a slowdown.
Barrels from Iraq, Qatar and Kuwait have also been ferried through Hormuz, according to vessel-tracking data compiled by Bloomberg, as well as Kpler and Vortexa data.
Saudi Arabia has not yet shuttled large volumes of its own barrels through Hormuz, but there are tentative signs of more activity from the kingdom’s Gulf ports now that its alternative Red Sea route faces pressure from Yemen’s Houthi militants. Two ships were seen loading at the Ras Tanura export hub last week, and Saudi tanker company Bahri has been positioning vessels off Oman’s coast. Sixteen supertankers are there now, with three more due in coming days, collectively capable of hauling 38 million barrels.
Insurers report a steady stream of requests from Gulf producers seeking cover for the trade.
‘It’s a dark trade,’ said Pankaj Khanna, chief executive of Heidmar Maritime Holdings Corp. ‘It’s the only option right now as not all owners are willing to take the risk.’
People with knowledge of Hormuz transits said more incidents had occurred than were publicly acknowledged, including both attacks on merchant ships and defensive actions by western forces. Several seafarers have died making the crossing and a growing number of oil spills have appeared in the Gulf of Oman, one visible in satellite images last week with no identified source.
