The U.S. credit rating was downgraded by Moody's Ratings on Friday, highlighting investor concerns about the government's growing debt.The downgrade from the top rating of Aaa to Aa1 "reflects the increase over more than a decade in government debt and interest payment ratios to levels that are significantly higher than similarly rated sovereigns,

Moody’s has downgraded the long-term senior unsecured debt ratings of Fannie Mae and Freddie Mac to Aa1 from Aaa, following its May 16 downgrade of the U.S. government.

U.S. stocks are drifting lower, while U.S. bonds and the value of the U.S. dollar are falling more sharply on Monday following the latest reminder that the U.S government seems to be hurtling toward an unsustainable mountain of debt.