United Airlines Holdings Inc. fell 0.7% at 11 a.m. in New York, while Delta lost 0.7% and American Airlines dropped 0.9%. Among cruise-ship operators, Carnival Corp. declined 1%, Royal Caribbean Cruises Ltd. retreated 1.3% and Norwegian Cruise Line Holdings Ltd. fell 2.2%. The S&P Supercomposite Airlines Index and an index of casinos and gaming names, which benefit from a reopening economy, are lower Monday, bucking the broader market that’s heading higher. 

U.S. flight cancellations exceeded 2,800 over the Christmas weekend, disrupting travel in one of the busiest periods of the year as the Omicron-fueled COVID wave triggered crew shortages. A winter storm in the northwest part of the country added to the difficulties on Sunday.

“The market will likely allow the situation a few weeks to play out to see if infection rates drop as they have in South Africa,” said Michael O’Rourke, chief market strategist at JonesTrading Institutional Services. If the infection rates remain elevated, “expect investors to express additional concern,” he added.

Delta and United cut at least 12% of their scheduled flights Saturday. The travel disruption adds to the impact from the Omicron variant, whose fast spread is causing havoc even though initial indications suggest it causes less-severe illness than other coronavirus strains.

It’s been a tumultuous year for travel-exposed stocks as investors have been forced to confront multiple coronavirus variants of varying severity.

The S&P 500 Airlines Index was one of the best-performing sectors over the first three months of the year but has since seen those gains evaporate after the Delta variant led to a spike in cases globally. Since Oct. 1, the gauge has fallen about 18%, making it among the worst-performing industry groups over that stretch.

—With assistance from Bre Bradham.