U.S. blocks Strait of Hormuz: Here's what's next for oil prices

The June 17 ceasefire between the U.S. and Iran is over. U.S. forces bombed more than 80 targets inside Iran over the July 12-13 weekend. Iran's Revolutionary Guard responded by closing the Strait of Hormuz again.

On July 13, President Donald Trump went on Truth Social and said the U.S. was putting the naval blockade back in place and charging every ship that uses the Strait a 20% toll on its cargo.

Oil moved before anyone had time to read the full post. Brent crude was up nearly 8% to $82.03. West Texas Intermediate moved the same amount to $77.10.

Just six vessels crossed the Strait in a 12-hour window on July 11. Before the fighting resumed, it was 18 to 22 a day, according to Al Jazeera. About 230 loaded oil tankers are sitting inside the Gulf right now with nowhere to deliver their cargo.

White House's new Hormuz blockade and 20% oil shipping toll explained

"The Hormuz Strait is OPEN, and will remain OPEN, with or without Iran. We are reinstating the THE IRANIAN BLOCKADE, so named because it is only stopping Iran's ships or customers from entering or leaving. All other countries will have fair and open use of the Strait," Trump wrote on Truth Social, as The Hill reported.

He said the U.S. would now be called "THE GUARDIAN OF THE HORMUZ STRAIT" and would collect 20% on all cargo shipped through it.

The blockade kicks in July 14 at 4 p.m. EST, according to Axios. It covers Iran's entire coastline, all ports, and oil terminals. Any ship entering or leaving those areas without U.S. authorization can be intercepted, boarded, and seized.

The International Maritime Organization (IMO) said that's a problem. "There is no legal basis through which to introduce mandatory tolls simply to transit through a strait," the IMO told CNBC.

Its 40-member council, which includes the U.S., said transit rights through international straits cannot be "threatened, impeded, denied, hampered, impaired or suspended."

On July 13, U.S. Central Command said the Strait was open and U.S. forces were there to keep it that way, The Hill reported. Iran's IRGC, on the same day, said it was closed. Two militaries, two different answers, same waterway.

Why the Strait of Hormuz matters so much to global oil prices

Before the U.S. and Israel hit Iran on Feb. 28, about a quarter of the world's seaborne oil trade and 20% of global LNG moved through the Strait of Hormuz every day, according to the Congressional Research Service. There's no fast alternative when it closes.

Saudi Arabia has pipelines that bypass the Strait to the Red Sea. Oman's location lets it route around it. Iraq, Kuwait, Qatar, and the UAE don't have those options. They ship through Hormuz, or they don't ship.

The 230 tankers stuck inside the Gulf right now are carrying oil that has nowhere to go until this gets sorted out.

Brent hit $114 on May 4 when things were at their worst. It had been drifting back down as the ceasefire held and more ships moved through. July 13 erased most of that progress. Whether it keeps going back toward $114 depends on how long this round lasts.

Oil price forecast as analysts assess Hormuz disruption risk

Saul Kavonic, head of energy research at MST Financial, said Iranian attempts to control the Strait will likely keep traffic below half of pre-war levels for months, with more flare-ups along the way, according to Al Jazeera.

Tony Sycamore at IG Australia pointed out that the U.S. and Iran never actually agreed on whether Hormuz is international waters or partly Iranian territory. That disagreement was in the ceasefire deal the whole time, just quietly sitting there. "At the very least, it will keep markets on edge," he wrote to clients.

President Trump had told reporters that oil prices would come down and this would "end very quickly," Politico reported. He said he didn't think the situation would go back to full-scale war. Oil going up nearly 8% in a session says the market isn't taking that promise at face value.

What the Hormuz oil blockade means for inflation, consumers, and the Fed

When crude moves 8% in a day, it doesn't stay in the energy sector. Gasoline goes up. Heating oil goes up. Jet fuel goes up. Airlines feel it. Trucking companies feel it. Anyone moving goods around feels it. That happens fast.

PCEinflation was already running well above the Fed's target through the first half of 2026. An oil spike landing on top of that is a problem the Fed didn't need more of. Citi analysts have warned previously that sustained crude gains can feed through into broader inflation in ways that force central banks to keep rates higher for longer.

The 20% toll makes it worse. Every ship using the Strait pays it, whether or not it has anything to do with Iran. That's a straight cost increase on goods moving through, on top of whatever supply-risk premium is already built into the price of oil.

What investors should watch as Strait of Hormuz standoff continues

The U.S. hasn't done a naval blockade at this scale since the Cuban Missile Crisis, according to CNN. There was no playbook for it then, and there isn't one now. U.S. military officials were still working out the logistics on July 13, hours after Trump posted.

Oil stocks, refiners, and energy infrastructure names move with crude. Airlines, manufacturers, and retailers with heavy fuel costs move the other way.

That's the basic trade. How long it stays that way depends on whether the diplomatic track picks back up or whether the coming days bring another round of strikes.

Iran's foreign minister Abbas Araghchi took a different angle. Rather than rejecting the toll concept, he used it to argue that Iran, not the U.S., should be the one collecting it.

"POTUS is absolutely right. Whoever provides secure and safe passage of commercial vessels through the Strait of Hormuz should be compensated for this service. Iran has always been the GUARDIAN of the Strait and will remain so FOREVER," he wrote on X. "20% is of course too much. We will be fair."

That's a strange position to take while also claiming you control the Strait and the U.S. doesn't. But it's the kind of opening that could eventually lead somewhere, if anyone in Washington and Tehran is still talking.

Related: White House makes promise on Strait of Hormuz and oil

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This story was originally published July 13, 2026 at 3:47 PM.