US equity futures slid overnight after President Donald Trump declared the tentative ceasefire with Iran over, triggering an immediate risk aversion move across global markets. The S&P 500 and Nasdaq 100 futures dropped roughly 0.5% each in early electronic trading, while Treasury yields dipped as investors sought safety.

The statement injects fresh uncertainty into a region that supplies a third of the world's seaborne oil. Oil prices jumped more than 2% on the news, with Brent crude reclaiming the $75 level, as traders priced in potential supply disruptions if hostilities resume. Energy stocks outperformed the broader index, while airline and travel shares came under pressure on higher fuel-cost expectations.

Defense contractors such as Lockheed Martin and RTX saw modest pre-market gains, reflecting the market's tendency to reward military-exposed names during escalation scares. Meanwhile, the VIX volatility index ticked above 18, signaling that options traders are demanding higher premiums for downside protection. The reaction highlights how thinly positioned equity markets remain ahead of this week's inflation data and Federal Reserve commentary.

For portfolio managers, the episode underscores how quickly geopolitical headlines can override economic data in driving short-term market direction, leaving investors to price in a wider range of outcomes for Middle East oil flows and regional stability.