NEW YORK, June 14 -- United States equity markets posted their biggest single-day gain since April on Thursday following President Donald Trump's announcement that he had called off the planned strikes on Iranian nuclear infrastructure and was finalising a memorandum-of-understanding framework with Iran's Ministry of Foreign Affairs that could be signed within days. The S&P 500 rallied 1.8 percent to close at 6,847, the Nasdaq Composite jumped 2.5 percent to 22,418, the Dow Jones Industrial Average gained 1.9 percent to 44,672, Brent crude futures slipped about 1 percent to close below $89.50 per barrel for the first time since late March, and the cumulative-Hormuz risk-premium that has been distorting cross-asset pricing through the 2026...