Joe Mazzola of Charles Schwab breaks down the April STAX report, which reflects the overall sentiment and strategies of Schwab investors each month. Caution continued for a second month, and buying rotated into ETFs and away from higher-beta tech. Net sells included Nvidia (NVDA), Amazon (AMZN), AMD (AMD), and Intel (INTC). Overall, STAX fell 10.6% in April to 50.1. However, Joe warns that Tax Day could have skewed the trend.