Geopolitical tensions between Iran and the United States are weighing on global markets, with Asia-Pacific indices poised for a lower open. Risk aversion is already visible in U.S. trading, where the S&P 500 dropped 0.4 percent to 7,337 and the Dow Jones fell 0.6 percent to 49,597. The Russell 2000, representing smaller companies, saw a steeper decline of 1.6 percent to 2,840. Investors are recalibrating portfolios for increased uncertainty, favoring defensive plays and re-evaluating growth stock valuations.

The broader market weakness masks notable strength in key technology names driven by specific catalysts. Nvidia rose 1.8 percent to $211.50, and Microsoft gained 1.7 percent to $420.77. Both companies continue to benefit from robust demand for artificial intelligence infrastructure, a trend that appears insulated from short-term geopolitical shocks. Meta Platforms also climbed 0.6 percent to $616.81, showing resilience in its advertising revenue outlook despite macro concerns.

Heightened Iran-U.S. tensions often drive crude oil prices higher, which could pressure corporate margins across several sectors. Any sustained move in oil futures above $90 per barrel would likely trigger further re-evaluation of earnings estimates for impacted sectors, creating headwinds for companies like airlines and logistics firms.

Investors should monitor official statements from the U.S. State Department regarding the clashes for any signs of de-escalation or further escalation. Such developments will dictate near-term market sentiment and volatility. The upcoming corporate earnings season, set to begin in two weeks, will provide the next major catalyst for individual stock performance, offering clarity on company-specific resilience against these macro headwinds.