U.S.–Iran War and Energy Markets

The S&P 500 climbed 0.8% on April 15, 2026, setting a fresh all-time high as U.S. investors increasingly bet that the war with Iran will be resolved quickly. The rally — which pushed the index past its January peak — came after a nearly 10% slide into a late-March correction and a more than 10% rebound over roughly two weeks. Traders pointed to reports that U.S. and Iranian officials had reached an "in principle agreement" to extend a ceasefire and allow further diplomacy, and markets reacted to signs that Persian Gulf oil flows could normalize rather than trigger a worst-case global economic shock.