Last night, U.S. stocks saw a massive surge in trading volume, marking the third-highest intraday trading volume since 2008. Although the triple witching day played a role, the trading volume far exceeded the usual levels for such days. Personally, I think the driving factors include: - Triple witching day, where stock options, index options, and index futures all expire simultaneously, leading to high trading volumes; - Rate cuts driving increased risk appetite and boosting liquidity; - Fundamentals improving as we enter October and approach earnings season. Among companies that have already issued Q3 earnings guidance, over 22% are expected to beat analyst expectations, hitting the highest level in a year. Triple witching day expirations are also a time for investors to adjust their positions, which reflects market sentiment.