Citadel Securities has reported a significant shift in retail investor behavior, with net selling of U.S. stocks and options last week. This marks a departure from the consistent buying trend observed over recent years. In March, net expenses fell by 55% from February and 70% from January's peak. Options trading has increasingly focused on defensive strategies, with heightened demand for downside protection. Historically, such retail selling has often been followed by a short-term rally in the S&P 500, averaging a 4.1% gain over two months. This change in investor behavior occurs amid market volatility driven by rising oil prices and geopolitical tensions with Iran, contributing to a 5% decline in the S&P 500 year-to-date, while Brent crude prices have surged by 80%.