Sellers stepped up to start September, pushing the Nasdaq below its 50-day and 21-day moving averages. Investors are growing more nervous about the slowing U.S. economy, with signs of weakness across consumer spending and manufacturing popping up over the last several sessions. There could be more near-term selling and volatility as Wall Street waits for the Fed to officially start cutting rates when its two-day FOMC meeting ends on September 18. The presidential election cycle adds to the unknowns. Yet, th ...