US stocks are bracing for their worst week since April, with major indices like the S&P 500 and Nasdaq showing significant pullbacks. This downturn is fueled by concerns over high valuations in speculative assets, particularly technology shares and Bitcoin, which has slumped over 30% from its peak. Global markets are also experiencing their steepest drop in seven months, with approximately $5 trillion wiped from recent gains. Investor sentiment is further dampened by doubts about future US interest rate cuts and the long-term impact of AI spending. Technical indicators suggest a bearish trend is strengthening.