Global markets tumbled Thursday as Iran's newly appointed supreme leader Mojtaba Khamenei vowed to keep the Strait of Hormuz closed indefinitely, sending oil prices above $95 a barrel and pushing US stocks down more than 1%. The Dow lost over 500 points while the S&P 500 extended its losing streak to three days. With roughly a fifth of the world's oil supply flowing through the waterway, analysts are calling it the largest supply disruption in oil market history.

Global markets tumbled on Thursday as Iran's new supreme leader issued a stark warning that the Strait of Hormuz would remain closed, deepening fears of a prolonged energy crisis and sending shockwaves through financial markets worldwide.

Mojtaba Khamenei, in his first public message since assuming power, declared the critical waterway would continue to serve as a "tool of pressure," and issued a direct threat that US military bases across the region "will be attacked" unless they shut down. The message, broadcast on Iranian state television, rattled investors who had been hoping for a diplomatic breakthrough.

US stock indexes fell sharply in response. The Dow Jones Industrial Average shed more than 510 points, a drop of 1.08%, while the S&P 500 declined 1% — extending its losing streak to three consecutive sessions. The tech-heavy Nasdaq Composite suffered the steepest losses, falling 1.3%.

Oil markets surged. US crude prices jumped nearly 10%, reaching $95.83 per barrel, while Brent crude — the international benchmark — climbed above $100 per barrel for the first time in years.

The Strait of Hormuz is the world's most critical energy chokepoint. Roughly 20% of global oil consumption passes through the narrow passage off Iran's southern coast, and its effective closure since the conflict began has upended global energy markets. The International Energy Agency, in its monthly report released Thursday, described the disruption as the largest supply shock in the history of the global oil market.

"The implicit closure of the Strait of Hormuz remains the hinge factor for global markets," said Felix Vezina-Poirier, chief strategist at BCA Research.

US Energy Secretary Chris Wright struck a firm tone, saying the strait "needs to be and will be reopened" as American military operations in the region continue.

The broader market reaction reflected deep anxiety among investors. The VIX — Wall Street's fear gauge — surged 9%, and CNN's Fear and Greed Index moved into "extreme fear" territory. Treasury yields climbed, with the 10-year note rising to 4.24%, its highest since February, as inflation expectations rose alongside oil prices. The US dollar strengthened against most major currencies, benefiting from safe-haven demand.

With no signs of a diplomatic resolution, analysts warn that energy markets — and the broader global economy — could face sustained turbulence for weeks to come.

Source: https://edition.cnn.com/2026/03/12/investing/us-stocks-oil-iran