Oil Plunges Below $100 Amid Iran-US Tensions

Global markets swung sharply this week as tensions between the United States and Iran intensified, pushing investors to reprice energy risk and broader equity exposure. Trading patterns shifted repeatedly as official signals alternated between escalation and restraint.

Early in the week, crude prices jumped and US stock futures weakened after Washington issued threats aimed at Iranian infrastructure. Later, a partial recovery followed when the US signaled a step back from escalation, briefly easing immediate fears of a wider conflict.

What changed in markets

Oil’s move captured the mood swing: Brent crude dropped below $100 a barrel after trading above $112. In equities, the S&P 500 reversed from an early expectation of a roughly 1% daily decline to a 1.5% gain during the rebound.

That relief did not hold. By Tuesday, Iranian officials rejected US assertions that talks had been productive, and Iran launched missile strikes into allied territories, after which oil prices rose again and stock gains faded.

Why investors are focused on control of the trajectory

The repeated reversals suggested to many market participants that Tehran may have substantial influence over how long the confrontation lasts and how intense it becomes. That perception matters because it can keep a risk premium embedded in energy prices even when US messaging turns more cautious.

By Thursday, the S&P 500 fell 1.78% and closed at a new low for the year, while Brent remained elevated compared with levels seen after the brief de-escalation signal. The sequence contrasted with earlier episodes—such as tariff disputes—when shifts in US policy direction were often enough to calm markets.

Energy chokepoint risk and stated conditions

The Strait of Hormuz remains central to the uncertainty because of Iran’s ability to disrupt flows through the passage. The source material cites potential disruption of 12.5 million barrels of oil and 11.5 billion cubic feet of gas per day moving through the strait, a scale that would have global consequences for energy supply and pricing.

The situation is further complicated by Iran’s stated conditions for ending the conflict, which were described as including recognition of its sovereignty over the Strait of Hormuz and reparations. The source does not provide details on whether these conditions are part of formal negotiations, nor does it specify any timeline or verification of the demands.

What it means for global markets

For investors, the week’s price action underscored how quickly geopolitical headlines can transmit into commodities and then into equities via inflation expectations and risk appetite. Elevated crude can feed into transport and manufacturing costs globally, while equity drawdowns can tighten financial conditions beyond the US.

Key uncertainties remain: the durability of any de-escalation signals, the scope of further strikes, and whether talks—if they occur—produce verifiable outcomes. Until those unknowns narrow, markets may continue to trade headline-to-headline, with energy-sensitive sectors and import-dependent economies most exposed.