Stocks are closing lower on concerns about the strength of the economy and the potential for a budget fight in Washington.
The Dow Jones industrial average fell 49 points to close at 15,401 Monday, logging its third straight day of declines. The Standard & Poor's 500 index fell eight points to close at 1,701.
Both indexes have given up all the gains that followed the Federal Reserve's surprise decision last Wednesday to keep its economic stimulus program intact.
Financial stocks led the declines on Monday. Citigroup dropped $1.64, or 3 percent, to $49.57 after reports that it suffered a drop in trading revenues that could crimp earnings.