In brief
Mohsen Rezaei, secretary of Iran's Supreme National Security Council, said on September 6 the country will declare in the coming days a no-go zone in the Gulf, starting where the US blockade begins, and that ships entering it will go on a sanctions list, per CNN Brasil and Exame.
The announcement came a day after US Central Command reported strikes on three Iranian tankers on September 5, one near Kharg Island, the country's main export terminal, in retaliation for missiles fired at US Navy ships, per CNN Brasil.
Traffic through the Strait of HormuzGeopolitical riskThemeRisk that conflicts or tensions between countries alter trade, energy, logistics and confidence.Open in the Market Map ↗ fell to about 10 commercial ships a day in the ten days through September 7, a third of pre-conflict flow and the lowest since May, per Kpler data cited by CNN Brasil; BrentOilAssetEnergy commodity whose price reflects supply, demand, inventories, logistics and geopolitical risk.Open in the Market Map ↗ rose 0.8% to above US$ 97.
What we know
05Verified fact · material
Mohsen Rezaei, of Iran's Supreme National Security Council, said on September 6, 2026 the country will declare in the coming days a no-go zone in the Gulf near the Strait of HormuzGeopolitical riskThemeRisk that conflicts or tensions between countries alter trade, energy, logistics and confidence.Open in the Market Map ↗.
It is Iran's formal escalation over Gulf navigation.
Verified fact
Per CNN Brasil, US Central Command reported strikes on three Iranian tankers on September 5, one near Kharg Island, after missiles were fired at US Navy ships.
It records the military trigger of Iran's announcement.
Sources[01]Verified fact
Per Kpler data cited by CNN Brasil, about 10 commercial ships a day crossed Hormuz in the ten days through September 7, a third of pre-conflict flow; BrentOilAssetEnergy commodity whose price reflects supply, demand, inventories, logistics and geopolitical risk.Open in the Market Map ↗ rose 0.8% to above US$ 97.
It measures the effect on flow and price.
Verified fact
Per Estadão Conteúdo via CNN Brasil and AFP via Correio Braziliense, Iran had already struck US bases in Kuwait and the UAE on September 3; Bloomberg Línea reports two tankers hit on September 5, against three at CNN Brasil.
It records the week's history and the count discrepancy.
Transmission to assets
Market read-through
For oilOilAssetEnergy commodity whose price reflects supply, demand, inventories, logistics and geopolitical risk.Open in the Market Map ↗, the no-go zone on top of the US blockade further cuts flow through Hormuz and keeps the risk premium in BrentOilAssetEnergy commodity whose price reflects supply, demand, inventories, logistics and geopolitical risk.Open in the Market Map ↗, which favors revenue for Petrobras, Prio and Brava.
For Brazil, BrentOilAssetEnergy commodity whose price reflects supply, demand, inventories, logistics and geopolitical risk.Open in the Market Map ↗ near US$ 97 pressures gasoline and diesel prices just as the fuel subsidy expires on September 9.
Portfolio impact
01An additional navigation restriction in Hormuz cuts physical supply and raises the barrel's risk premium.
Positive for oilOilAssetEnergy commodity whose price reflects supply, demand, inventories, logistics and geopolitical risk.Open in the Market Map ↗ prices; negative for global risk.
What would change the view: The read changes if the zone is not enforced or if a ceasefire comes.
Direction is an explanatory hypothesis, not a forecast or recommendation.
Next signals
What to watch
- Publication of the no-go zone's coordinates by Iran and the US response.
- Kpler daily data on Hormuz traffic and BrentOilAssetEnergy commodity whose price reflects supply, demand, inventories, logistics and geopolitical risk.Open in the Market Map ↗'s price at the week's open.
Limits of the reporting
What remains uncertain
- The number of tankers hit on September 5 differs: three at CNN Brasil, two at Bloomberg Línea; Iran's version of the damage was absent from verified coverage.