US stocks closed lower on Thursday, as worries over bad loans at regional banks and persistent US-China trade tensions weighed on sentiment. The S&P 500 dropped 0.6%, the Nasdaq 100 fell 0.5%, and the Dow Jones lost 302 points. Zions Bancorporation plunged 13% after reporting loan losses, while Western Alliance tumbled 10.8% amid a fraud lawsuit against a borrower, stoking concerns about credit quality. Earlier in the session, chipmakers like TSMC boosted markets after raising revenue forecasts and reporting strong profits, supporting optimism around AI demand. Investors also watched rising geopolitical risks, with Trump warning that the US is “in a trade war now” and threatening further tariffs on China. The third week of the US government shutdown added further uncertainty, delaying key economic data and contributing to a choppy market environment.