Oil Breaks Above $100 and Knocks Global Stocks Lower as Yields Climb

Global equities have come under pressure as surging oil prices rattle investors. Benchmark Brent crude futures have pushed back above $100 a barrel, a psychologically important level for markets, sending the S&P 500 and other major US stock indexes lower on September 9. The spike reflects renewed tension around Iran and concerns over potential supply disruptions through the Strait of Hormuz, a key chokepoint for global crude shipments.

At the same time, the US 10‑year Treasury yield has climbed into the 4.8% area, near its highest levels since the autumn of 2023. Rising long‑term yields tend to weigh on equity valuations, particularly growth and technology names that are priced on expectations of distant future earnings. Investors are increasingly focused on the risk that higher energy costs reignite inflation just as the Federal Reserve heads into its September policy meeting with odds of another rate hike creeping higher.

Energy shares, which benefit from higher oil prices, have outperformed the broader market, underscoring a sharp divergence between sectors. From here, upcoming US inflation reports and weekly petroleum inventory data will be key catalysts for expectations on both inflation and interest rates, and thus for global risk assets. In the near term, equities, bonds and commodities are likely to move more tightly together via shifting inflation expectations, putting portfolio‑level risk management in the spotlight.