Key keywords: Iran-US diplomatic progress, global stock market rally, crude oil price stabilization, Middle East de-escalation, S&P 500 gains, energy sector outperformance, Nasdaq upward momentum, geopolitical risk reduction, cross-border trade outlook, emerging market asset rebound. Reports of preliminary diplomatic breakthroughs between Iran and the United States over nuclear program constraints and regional security commitments sent global equities surging during Wednesday’s trading session, as investors priced in sharply reduced geopolitical risk across the energy-rich Middle East. For months, markets had priced in a persistent risk premium for oil and risk assets broadly, as repeated escalations between the two nations including naval skirmishes in the Strait of Hormuz and targeted sanctions on Iranian energy exports raised fears of a full-scale regional conflict that could disrupt nearly 20% of global crude oil supplies. Early Wednesday, anonymous sources from both diplomatic delegations confirmed that negotiators had reached tentative agreements on 7 core points, including a partial rollback of US sanctions on Iranian oil exports in exchange for verifiable limits on Iran’s uranium enrichment activities, plus a joint commitment to de-escalate proxy conflicts across Yemen, Syria and Lebanon. The S&P 500 closed 2.1% higher on the day, marking its largest single-day gain in three months, with energy stocks leading the rally with an average 4.3% uptick as oil prices stabilized at $78 per barrel, down 6% from the 3-month high hit last week amid conflict fears. The Nasdaq Composite added 2.4%, as tech stocks benefited from reduced expectations of inflationary pressure from elevated energy costs, while European and Asian equities also posted broad gains, with the Euro Stoxx 50 up 1.8% and the MSCI Emerging Markets Index rising 2.3% on the day. Tom Henderson, chief global strategist at JPMorgan Asset Management, noted in a client note that "the de-escalation between Iran and the US removes one of the biggest tail risks hanging over global markets for 2024. If the preliminary deal holds, we could see oil prices stay in the $75-$80 range through the rest of the year, which would take significant pressure off central banks struggling to bring inflation back to target." Market observers noted that while the preliminary agreement still needs formal ratification from both governments, the clear signs of progress have already shifted investor sentiment from risk-off to risk-on, with capital flows into emerging market assets and cyclical stocks picking up sharply in afternoon trading. Analysts also highlighted that the potential return of over 1 million barrels per day of Iranian crude oil to global markets would help address supply tightness that has been a key driver of inflation over the past two quarters. The positive market momentum is expected to extend into Thursday’s trading session, with futures contracts for all major US indices pointing to further gains in pre-market trading as more details of the preliminary agreement are expected to be released to the public.