Iran has re-closed the Strait of Hormuz just days after signing a memorandum of understanding with the United States that was meant to reopen the critical waterway. The reversal came as oil flows through the strait had already begun to rebound, and online prediction markets are now showing slightly higher odds of a related disruption event.
The MoU and the reversal
Under the MoU, signed less than a week ago, Iran and the US agreed to restore normal passage through the Strait of Hormuz, through which about a fifth of the world's oil passes. But Tehran moved to re-close the strait without warning, reneging on the agreement almost immediately. The reasons for the abrupt about-face remain unclear.
Oil flows and market reaction
Before the re-closure, crude tanker traffic had started to pick up again. The brief reopening had brought some relief to global energy markets, which had been bracing for supply disruptions. Now, with the strait shut again, shippers and buyers face renewed uncertainty. No major price swings have been reported yet, but traders are watching closely.
Polymarket odds tick up
On Polymarket, a decentralized prediction platform, the “Yes” odds for an event related to the Strait of Hormuz rose to 2.55%. While still low, the increase signals that a small but growing number of bettors expect further instability in the region. The specific event is tied to a military or political flashpoint, though the platform's contract details are not publicly available.
The odds had been near zero before the MoU was signed, then dropped further during the brief reopening. The uptick reflects the market's recalibration after Iran's decision to re-close.
What prompted Iran to walk away from the deal so quickly? Neither government has issued a statement explaining the change. The US has not yet responded publicly, and shippers are left guessing when—or if—the strait will reopen again.
