The Dow Jones Industrials dropped 14.79 points to 31,485.89.
The S&P 500 fell 3.73 points to 3,908.01.
The tech-heavy NASDAQ subtracted 30.52 points to 11,577.10.
Cruise names dragged the market lower Monday. Royal Caribbean fell 4.5%, while Carnival and Norwegian Cruise declined about 3% each.
Etsy was another top decliner, down more than 4% following a downgrade by Needham.
The energy sector was a notable gainer, with Devon rising 5%. Valero, Enphase and Occidental were each up more than 4%.
BioNTech shares advanced almost 4% after the drug maker said its Omicron-based COVIF-19 booster generates an improved immune response against that variant.
Meanwhile, shares of Spirit Airlines fell more than 7% after the company said it would accept the latest takeover bid from Frontier Group.
Nike will report earnings for its fiscal fourth quarter after the bell Monday, ahead of a handful of other key reporters this week including Bed Bath & Beyond, General Mills, Constellation Brands and Walgreens.
Traders are also watching for the pending home sales report, due out later this morning.
Treasury prices were lower, raising yields to 3.17% from Friday’s 3.14%. Treasury prices and yields move in opposite directions.
Oil prices fell 95 cents to $106.67 U.S. a barrel.
Gold prices slid 40 cents to $1,829.900 U.S. an ounce.