Oil markets responded with rising prices as Iran's Revolutionary Guard warned of a complete cutoff of energy exports from the Middle East in retaliation for the U.S. reinstating its blockade of Iranian ports. This escalation compounds concerns over the security of oil transport through the critical Strait of Hormuz, a narrow passage where a significant share of the world’s oil passes.

Brent crude, the global benchmark, increased by 63 cents to reach $85.36 a barrel, while U.S. benchmark crude futures rose 46 cents to $79.80. These movements reflect heightened fears over potential disruptions fueled by renewed military tensions between the U.S. and Iran. The Iranian side emphasized that oil and gas exports from the region would be available either equitably or not at all, signaling an all-or-nothing stance amid the escalating conflict.

The backdrop to these market fluctuations includes President Donald Trump’s announcement that the U.S. has resumed its blockade on Iranian ports, following the collapse of a temporary agreement intended to de-escalate ongoing hostilities. Analysts note that the fragile memorandum of understanding between the two nations has failed, with military exchanges intensifying and regional shipping routes becoming increasingly hazardous.

In the financial sector, major U.S. banks posted strong second-quarter results, buoyed partly by trading gains linked to market volatility arising from the conflict. Morgan Stanley reported record quarterly revenue and profits, contributing to moderate premarket gains in U.S. stock indexes. The S&P 500 futures inched up while Dow Jones futures held steady. The Nasdaq futures showed a more pronounced increase, reflecting investor optimism despite geopolitical risks.

Meanwhile, European stock markets opened cautiously as concerns over inflation and geopolitical tensions weighed on investor sentiment. Reports expected later in the day, like the U.S. wholesale inflation figures for June, are likely to influence market directions amid this unstable environment.