The U.S.’s deteriorating fiscal situation is threatening to spoil Wall Street’s good mood.

Investors sold U.S. government bonds and the dollar on Monday, after Moody’s Ratings late last week stripped the U.S. of its last triple-A credit rating, citing large budget deficits and rising interest costs. Adding to the nerves about America’s debt trajectory, the House Budget Committee approved a tax-and-spending bill Sunday that is projected to add trillions of dollars to those deficits.