U.S. stocks closed sharply lower on Friday, with the S&P 500 falling 1.1% to record its biggest weekly decline since June. The Nasdaq 100 dropped 2.5% on the day, marking its worst weekly performance since April 2025. A surge in oil prices reignited inflation concerns, while growing skepticism over the sustainability of the AI investment boom continued to weigh heavily on semiconductor stocks. Cloud computing provider CoreWeave saw its shares plunge, further intensifying the broader tech sell-off.