The S&P 500 Just Shrugged Off the Iran War and Hit a New Record High. But Are Investors Too Bullish?

Geopolitical tensions have been raging in the Middle East since Feb. 28, centered around a direct conflict between the U.S. and Iran. Oil prices have soared as the region grapples with attacks on critical infrastructure and the effective closure of shipping lanes in the vital Strait of Hormuz.

As I write this, the price of a barrel of West Texas Intermediate crude is up 60% since the start of 2026. That means American consumers are facing higher prices not only at the gas pump, but for practically every product that travels on a boat, plane, or truck.

The S&P 500 (SNPINDEX: ^GSPC) stock market index recently plunged by as much as 9% from its peak as investors weighed the potential negative impacts to corporate earnings and the broader economy. However, sentiment turned on a dime on April 8 when the U.S. and Iran reached a ceasefire agreement. The index has since recovered all of its losses, and it closed at a fresh record high on April 15.

But with oil prices still elevated, are investors simply too bullish right now?

Image source: Getty Images.

A wave of positive news

Around 20 million barrels of oil transited the Strait of Hormuz every day before the war, representing 25% of the world's seaborne supply, so the disruptions to this critical waterway stoked fears of a global energy shortage.

However, the initial oil supply constraints weren't as severe as originally feared. Iran continued to ship roughly 1.8 million barrels per day out of its ports even after the conflict started, while Saudi Arabia used its East-West pipeline to reroute approximately 7 million barrels per day to its ports in the Red Sea instead. The United Arab Emirates also has a strategic pipeline capable of moving 1.5 million barrels per day beyond the Strait.

When you add the ceasefire to that supply picture, I'm not surprised investors have piled into the stock market with so much conviction over the last week or so. But some unrelated developments have also bolstered sentiment.

First, according to the latest non-farm payrolls report from the U.S. Bureau of Labor Statistics (released on April 3), the economy created a whopping 178,000 jobs in March. It blew away economists' consensus estimate of 60,000 new jobs, and it reversed the 133,000 job losses from February. An investor should never hang their hat on one data point, but this report was an early sign that the economy might be taking higher oil prices in stride.

Second, major U.S. banks like JP Morgan Chase, Goldman Sachs, and Bank of America reported their operating results for the first quarter of 2026 this week, and they mostly topped Wall Street's expectations. Banks are on the front line of the economy; when consumers and businesses feel confident, they spend more money and their appetite for credit rises, so these reports added more fuel to investors' renewed bullishness.

Are investors too bullish?

With the economy seemingly holding up and the S&P 500 at a fresh record high, it's rational to feel enthusiastic about what might be coming next. However, there are some real risks to consider.

For example, oil prices are still a long way from pre-war levels, which is likely to stoke inflation. The Producer Price Index soared to an annualized rate of 4% in March, which was the highest level in three years. This measures how quickly input costs are rising for manufacturers and service providers, which are often passed onto consumers.

Therefore, the economy isn't out of the woods yet -- and if wholesale inflation feeds through to the more widely followed Consumer Price Index (CPI) in a meaningful way, the U.S. Federal Reserve might have to consider raising interest rates later this year. Higher borrowing costs usually put a dent in consumer spending and business investment, which would be bad news for corporate earnings and the stock market.

The S&P 500 has recovered to new highs after every sell-off, correction, and even bear market since its inception in 1957, so there is never a bad time to put money to work as long as investors maintain a long-term outlook of at least five years. However, with clear economic risks lurking, it might be wise to invest a small sum of money in stocks consistently each month for the foreseeable future, rather than parking a significant lump sum in the market right now at record highs.

Bank of America is an advertising partner of Motley Fool Money. JPMorgan Chase is an advertising partner of Motley Fool Money. Anthony Di Pizio has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Goldman Sachs Group and JPMorgan Chase. The Motley Fool has a disclosure policy.