Why the Dollar and Brent Oil Are Moving Together During the Iran War

First, the conflict threatens global energy supply. Brent crude surged sharply after disruptions linked to the war and fears that tanker traffic through the Strait of Hormuz could be restricted.

Second, the war has triggered global risk aversion. Investors often move capital into dollar assets during periods of geopolitical tension, increasing demand for the U.S. currency.

When these forces occur simultaneously, oil rises because of supply fears while the dollar rises because of safe‑haven demand—causing both assets to move in the same direction.

Why the Strait of Hormuz Matters So Much

Much of the market reaction centers on the Strait of Hormuz, one of the most critical energy chokepoints in the world.

About 20 million barrels of oil per day pass through the strait—roughly one‑fifth of global petroleum consumption and more than a quarter of seaborne oil trade.

Any disruption, or even the threat of one, creates an immediate supply risk for global energy markets. Traders typically price this risk into oil through a geopolitical premium, pushing Brent higher even before physical supply is actually reduced.

Inflation and Central‑Bank Expectations

Rising oil prices also feed directly into inflation expectations.

Higher energy prices raise transportation and production costs across the economy. During the Iran conflict, markets began pricing in the possibility that central banks—especially the U.S. Federal Reserve—might delay interest‑rate cuts because inflation risks remain elevated.

That dynamic can support the dollar: if interest rates are expected to stay higher for longer, dollar‑denominated assets become more attractive to investors.

The U.S. Energy Boom Changes the Currency Equation

Another structural shift behind the correlation is the United States’ transformation into a major energy exporter.

The U.S. has been a net exporter of energy for several consecutive years, producing more energy than it consumes.

Crude oil exports alone exceeded 4.1 million barrels per day in 2024, a record level according to the U.S. Energy Information Administration.

In earlier decades, rising oil prices were largely negative for the U.S. economy because the country depended heavily on imports. Today, higher oil prices can partly benefit the U.S. energy sector and trade balance, weakening the old assumption that expensive oil automatically hurts the dollar.

Global Currency Effects

The oil‑dollar combination creates particular pressure for energy‑importing economies.

When oil prices rise while the dollar strengthens, countries that import energy must pay more both because oil itself is more expensive and because their local currencies buy fewer dollars.

This “double squeeze” can widen trade deficits and raise inflation in importing economies, especially in Asia and emerging markets that depend heavily on Middle Eastern oil shipments.

Why This Matters for Market Volatility

A synchronized move in oil and the dollar can increase volatility across multiple asset classes.

Energy prices affect inflation and growth expectations, while dollar movements influence global financial conditions and capital flows. When both shift in the same direction, equities, bonds, currencies, and commodities may all react simultaneously to the same geopolitical headlines.

This is one reason analysts describe the Iran conflict as a cross‑asset shock, rather than a normal commodity rally.

What It Means for Hedging Strategies

For investors and companies, the biggest implication is that traditional correlations can break down during geopolitical crises.

Many hedging strategies assume that rising oil prices will weaken the dollar, helping offset currency exposure. But when both assets move together, those hedges may fail.

Companies exposed to energy prices—such as airlines, manufacturers, and shipping firms—may need to manage oil, currency, and interest‑rate risk separately rather than relying on historical relationships.

The Bottom Line

The record‑high correlation between the U.S. dollar and Brent crude during the Iran conflict reflects a rare combination of forces: supply fears around the Strait of Hormuz, safe‑haven demand for dollar assets, inflation concerns, and the United States’ growing role as an energy exporter.

These conditions can temporarily overturn the typical oil–dollar relationship. As long as geopolitical risk and energy supply concerns remain central to markets, the two assets may continue moving together rather than offsetting each other.

When the conflict risk fades and supply flows normalize, the traditional inverse relationship between oil and the dollar could gradually return—but history shows it is never guaranteed.