Morgan Asset Management's Global Chief Strategist David Kelly said the Federal Reserve should lower interest rates by 25 basis points on Wednesday, instead of the 50 basis points some market participants are calling for, to avoid panicking investors about the state of the U.S. economy. He said the Fed's long maintenance of high interest rates was a mistake. "But when they cut, they need to do it modestly because they don't want people to think they're panicking," Kelly added.