Stock market today: Dow, S&P 500, Nasdaq plunge, oil surges as fresh strikes intensify Iran conflict

Market Reactions - US stocks experienced a sell-off, with the S&P 500 declining approximately 1.6%, and both the Dow Jones Industrial Average and Nasdaq Composite dropping 1.8% due to escalating tensions in the Middle East [1] - The initial shock from the outbreak of US-Iran hostilities was somewhat mitigated on Monday, as major US indices rebounded from steep intraday losses, driven by dip-buyers [2] Geopolitical Impact - The recent Israeli-led air strikes on Iran and Lebanon are expected to exert pressure on global markets, with a focus on Iran's potential responses following attacks on oil infrastructure across multiple countries [3] - President Trump's comments regarding the possibility of a prolonged US military involvement have heightened fears of a drawn-out conflict, contributing to rising crude oil prices, which increased over 8.5% amid inflation concerns [4] Corporate Earnings - Investors are closely monitoring corporate earnings, with Target's shares rising in premarket trading after the company reported holiday and full-year sales that met Wall Street estimates [5] - Other companies reporting earnings on the same day include Ross Stores, AutoZone, and Best Buy, indicating ongoing investor interest in retail sector performance [5]