Wall Street rises on Apple-led tech gains

U.S. stocks have swung wildly since Friday on contrasting comments from Federal Reserve officials on whether the central bank would raise interest rates at its Sept. 20-21 meeting. "With a seasonal backdrop, high valuations and concerns over disparate monetary policies by central banks, it will likely remain a choppy environment," said Eric Wiegand, senior portfolio manager at the Private Client Reserve at U.S. Bank in New York. The CBOE Market Volatility index , known as Wall Street's fear gaug