U.S. stocks move in sync during sharp market selloff

The U.S. equity market experienced a rare period of synchronized movement last week, though the trend manifested as a broad-based decline rather than a rally. On Nov. 5, 430 members of the S&P 500 finished the session lower, representing the highest number of decliners in a single day since Dec. 31.

The market performance marked the worst session for the S&P 500 since the tariff-related volatility observed in April 2025. According to reports, the downturn was largely driven by investor concerns regarding potential policy changes following the U.S. midterm elections. Specifically, market participants expressed anxiety that newly empowered Democrats might implement regulations to slow the expansion of AI data centers.

The downward pressure was compounded by investors who had previously utilized leverage to bet on the growth of the AI sector. As prices fell, these market participants were forced to sell positions to cover losses and meet cash demands, further accelerating the decline.

Craig Johnson, a technical strategist at Piper Sandler, noted that the current market environment remains unstable. He advised that until support levels hold and market leadership stabilizes, investors should prioritize capital preservation over attempting to buy the dip.