Wharton professor and author Jeremy Siegel thinks the Federal Reserve will begin tapering its bond-buying program in September, and he thinks the move is already baked into stock prices. Siegel tells Bloomberg that unless the tapering accelerates quicker than expected, the bull market should continue. He stressed that the start of tapering doesn’t mean a dramatic cut to the stimulus the Fed is providing, and says he expects 2.5% to 3% GDP growth for the U.S. in the third quarter.