Why US-Iran tensions near the Strait of Hormuz push oil up and stocks down

Oil reacts first because Hormuz is a global chokepoint

The Strait of Hormuz is not just another shipping lane. The US Energy Information Administration said oil flows through the strait averaged 20 million barrels per day in 2024, equal to about 20% of global petroleum liquids consumption . The EIA also said flows through Hormuz in 2024 and the first quarter of 2025 made up more than one-quarter of global seaborne oil trade, while around one-fifth of global liquefied natural gas trade also transited the strait in 2024 .

That concentration explains why crude can jump before a confirmed supply loss appears. Traders do not need a verified long-term closure to add a risk premium; reports that tanker traffic could become unsafe, delayed or more expensive are enough to move prices. Pepperstone described supply-disruption risk through Hormuz as central to oil-market pricing during the latest US-Iran tension cycle .

Recent market snapshots show the pattern

The reported price moves are separate market snapshots, not one continuous price series. But they show the same direction of travel.

One report said Brent crude rose 3.8% to $112.30 a barrel and WTI rose by a similar margin to $105.60 after renewed concerns about the safety of transiting the Strait of Hormuz and Iranian naval claims involving US ships . Another market report described Brent jumping about 7% to $96.85 in early Asian trading, while S&P 500 futures fell about 0.9% as risk sentiment weakened . Business Insider also reported oil logging fresh gains and US stocks closing lower as traders assessed the risk that the Iran conflict could heat up again .

The immediate impact, then, is clearest in crude. Equity pressure tends to follow when investors begin to price the broader consequences of an oil shock .

Why stocks slide when oil jumps

Higher oil prices can affect equity markets through several related channels. Pepperstone said higher energy prices were lifting inflation expectations and could pressure global equities, while also noting support for gold in that environment . UBS likewise described global equities moving lower as Middle East conflict heightened oil-supply disruption concerns .

The mechanism is straightforward: if investors think energy costs will stay elevated, they may become more cautious about inflation, corporate costs and overall risk appetite. That does not mean every stock or market falls equally. The strongest point supported by the available sources is macro-level: oil is the main transmission route, and equity weakness follows when crude prices revive inflation concerns and risk-off trading .

Fear premium is different from physical disruption

The most important distinction is between a fear-driven risk premium and an actual sustained disruption in flows. The reports cited above describe oil moving on renewed concerns, naval claims and market anxiety around Hormuz . They do not, on their own, establish a lasting collapse in transit volumes.

That matters because the EIA said total oil flows through the Strait of Hormuz in the first quarter of 2025 remained relatively flat compared with 2024, even amid regional conflict . Standard Chartered also described oil as the main route through which the Iran conflict affects asset prices, said the market impact had been limited so far, and identified the key issue as how soon the Strait becomes safe enough for oil and gas tankers to navigate .

If tankers keep moving, an oil spike can behave like a geopolitical premium that fades when tensions cool. If safe passage is materially impaired for longer, the shock becomes more serious for both crude and equities .

What would make the market damage worse

Markets would likely react more severely to clear evidence that oil and gas tankers cannot safely transit Hormuz for a prolonged period. That would make elevated crude prices harder to dismiss as a temporary fear premium and would intensify the inflation and equity-pressure channels described by market analysts .

The main indicators to watch are simple:

• Safe passage for tankers. Standard Chartered says the key question is how soon Hormuz is safe enough for oil and gas tankers to navigate .
• Actual flow data. The EIA’s latest cited data showed flows in the first quarter of 2025 remained relatively flat compared with 2024, which is why claims of disruption should be separated from verified transit effects .
• Inflation and risk sentiment. Pepperstone links higher energy prices with rising inflation expectations and potential pressure on global equities .

Bottom line

Renewed US-Iran clashes near the Strait of Hormuz are bullish for oil and negative for stocks because the strait carries a large share of global energy trade and investors quickly price the possibility of disrupted transit . But the scale of the market damage depends on the difference between fear and flow: if the issue remains a risk premium, volatility can ease; if safe passage through Hormuz is genuinely impaired, the shock becomes much harder for global markets to absorb .