Seems like nobody is buying no matter how cheap stocks get! Why buy today when next week they will be cheaper! This could be a reason for a Crash.. Moodyâs, the well-known ratings agency, downgraded the U.S.âs AAA debt rating this morning. The move comes on the heels of debt ratings downgrades made over the past few months, including downgrades on Greeceâs debt and on Portugalâs debt. The downgrades on Greeceâs debt sent the European Unionâs monetary union into disarray for weeks. Of course, the fact that the U.S.âs sterling debt rating has now been tarnished is prompting even more widespread fear. The U.S. is the worldâs pre-eminent economy, so a debt ratings downgrade is big news â especially since U.S. Treasuries had formerly been seen as one of the safest investments in the world.