Major U.S. stock indexes fell sharply on Thursday as the financial markets finally absorbed the economic implications of the escalating conflict between the United States and Iran.

The sell-off was triggered by Brent crude oil surging past the $100-per-barrel threshold, a level not seen since May, marking a decisive shift in market sentiment from complacency to concern over supply disruption and inflationary pressure.

While equity markets had remained relatively flat during the initial phase of the renewed hostilities, the breach of the $100 mark acted as a catalyst for broader risk aversion.

While equity markets had remained relatively flat during the initial phase of the renewed hostilities, the breach of the $100 mark acted as a catalyst for broader risk aversion.

Investors are now grappling with the prospect of sustained higher energy costs, which threaten to erode corporate margins and consumer spending power.

The rapid repricing of geopolitical risk in energy markets has spilled over into equities, as traders adjust portfolios to account for the potential for a prolonged and costly conflict.

The U.S. military has conducted strikes against Iran for 12 consecutive nights, intensifying fears that the conflict could disrupt global oil supplies further.