Meanwhile, 30-year Treasury yields dipped to 2.8657 percent after finishing at 2.898 percent Friday.
Key data releases included new home sales for September, which fell 11.5 percent to an annualized rate of 468,000.
"For all the talk of low inventories of existing homes (which there certainly is), builders can't find enough warm bodies to build the homes which in turn raises labor costs and the ultimate price of the house which in turn leads to the 1st time buyer to rent instead of buy notwithstanding the strong rate of rent increases," Peter Boockvar, chief market analyst at The Lindsey Group, said in a note.
The Dallas Federal Reserve Survey business activity index came in at -12.7.
As for the Fed, it could tweak its language slightly when it releases its post-meeting statement Wednesday.
Many economists now expect a December rate hike if the economy does not slow significantly.