Charles Schwab clients diversified their portfolios throughout September, highlighted by what Joe Mazzola considers a unique trend in sharp ETF inflows. As he says, not just one ETF made the top 10 buys in the month, but five. Among the top equity buys in September: SpaceX (SPCX), Amazon (AMZN), Broadcom (AVGO), and Nvidia (NVDA). Meta Platforms (META), AMD Inc. (AMD), Palantir (PLTR), and Intel (INTC) were the top sells. Joe Mazzola sifts through all his data from Charles Schwab investors to explain how profit-taking and macro caution gripped momentum — and may continue to do so.