S&P 500 suffers biggest decline since October with the Fed mum on further aid

Getty Images / Bryan R. SmithUS stocks dropped on Wednesday as the Fed left interest rates unchanged and didn't promise further aid for the economy.Retail traders continued to wage a battle against hedge funds, sending the prices of heavily-shorted stocks soaring.Sign up here for our daily newsletter, 10 Things Before the Opening Bell.The S&P 500 faced its biggest decline since October while the Dow and Nasdaq tumbled as the Federal Reserve left its benchmark interest rate unchange