Jeremy Siegel says the bull market is intact, but Bernanke must be watchful

There's always things for the market to worry about. I start worrying when no one worries. Then we're at a top for the market.

In terms of when the Fed starts raising, history shows that, yes, there is a little tremble, a little correction that comes in, but the early tightening by the Fed does not stop a bull market. It's only the very late tightening when they really have to move against the excesses and the inflation that we really see stocks having trouble.

So, there certainly will be a flutter when Bernanke has to make that shift but my feeling is that won't stop the bull market. Also, one must remember that mild inflation, even 2 to 4%, a little bit above the Fed's target, has actually been a sweet spot for stocks historically. Stocks are real assets, they tend to move with prices, it gives corporations and firms pricing power, so I'm not worried about a mild inflation. I think that's not going to be a problem for stocks. Obviously anything more than that, 5, 6%, the Fed would have to move very aggressively.

~Jeremy Siegel, professor of finance, Wharton School of Business, Bloomberg News interview, March 24, 2011