Calamos Investments President & CEO John Koudounis reacts to Moody's downgrading the U.S.' credit rating and how the tax bill could impact market uncertainty.

The U.S. credit rating was downgraded by Moody’s, meaning all three major credit rating firms no longer give America their ...

Wall Street closed just before the US credit rating was cut by Moody's over concerns about mounting debt. Follow the day's ...