The Strait of Hormuz Has Been Shut Down—Here’s Why This Spells Major Trouble for Oil Prices and the S&P 500

How the Iran Conflict Is Shaping the 2026 Markets

The ongoing war involving Iran has become a central issue for global markets in 2026, with the potential to significantly influence the performance of the S&P 500 ((SNPINDEX: ^GSPC)). As of the latest data on Friday, the index—which tracks 500 of the world’s top companies—has dropped about 3% since the year began. This decline stands out, especially considering that the S&P 500 delivered annual returns exceeding 16% in each of the last three years, far surpassing its historical average of 10%.

The situation remains unresolved, and further escalation is possible. One of the most pressing new developments is the closure of the Strait of Hormuz, a move that could have major repercussions for oil prices and, by extension, the broader market. Understanding why this chokepoint matters is essential for anyone watching the stock market this year.

Why the Strait of Hormuz Matters for Global Markets

In an effort to exert pressure on the United States, Iran has shut down the Strait of Hormuz—a vital maritime passage in the Middle East. This strait links the Persian Gulf to the Arabian Sea and, ultimately, the Indian Ocean. Approximately one-fifth of the world’s oil supply is transported through this route. Unsurprisingly, oil prices have surged to levels not seen since 2022, with current prices hovering near $100 per barrel amid ongoing volatility.

Back in 2022, high oil prices coincided with soaring inflation, which peaked above 9%—a rate not witnessed in decades. That same year, the S&P 500 suffered a steep 19% decline.

While 2026 may not mirror the events of 2022 exactly, the outlook for the markets remains challenging. Elevated oil prices can drive up shipping expenses, which then filter down to consumers through higher product costs. As inflation climbs, the likelihood of interest rate cuts diminishes, potentially dampening investor sentiment. This chain reaction, triggered by disruptions in the Strait of Hormuz, could have lasting and widespread consequences for the markets, especially if the situation persists.

How Should Investors Respond to Market Uncertainty?

The Middle East conflict is unpredictable and could shift rapidly. Making investment decisions based solely on political or economic events can be risky. It’s worth recalling that Warren Buffett maintained his investments even during times of war—his first stock purchase was during World War II. By staying invested over the long term, he was able to benefit from market recoveries.

Modern investors might consider a similar approach. If your investment horizon is long and you don’t need immediate access to your funds, holding onto S&P 500 index funds could still be a wise strategy. Although volatility may persist due to the Middle East conflict, it doesn’t necessarily warrant exiting the stock market altogether.

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