Stock market today: Dow, S&P 500, Nasdaq fall as oil rises amid US-Iran tensions, 30-year yield hits highest level in decades

On Monday, US stocks suffered declines following increased concerns about the potential escalation of the US-Iran war. Dow Jones Industrial Average (^DJI) and S&P 500 (^GSPC) indexes both fell by 0.5%, while the tech-heavy Nasdaq Composite (^IXIC) dropped 0.3%. Oil prices surged to $90 per barrel, driven by fears of a renewed conflict, as Iranian officials expressed readiness to employ a more aggressive approach should tensions persist.

The 30-year Treasury yield (^TYX) reached its highest level since 2007, reaching 5.31%, reflecting investor concerns over the mounting national debt. President Trump's threat of military action against Oman in response to potential interference with the Strait of Hormuz added to market jitters.