Travel stocks drop on Omicron-related flight groundings Dec 27 (Reuters) - The S&P 500 index (.SPX) closed at a record high on Monday, its fourth straight session of gains, as strong U.S. retail sales underscored economic strength and eased worries from Omicron-driven flight cancellations that hit travel stocks. The rally is the longest since an eight-day streak that ended on Nov. 8. U.S. holiday season retail sales rose 8.5% from Nov. 1 to Dec. 24, powered by an ecommerce boom, according to a Mastercard Inc report, which helped the S&P 500 retailing index (.SPXRT)gain on the session. read more Travel-related stocks, typically sensitive to coronavirus news, declined after U.S. airlines canceled about 800 more flights on Monday after nixing thousands of flights during the Christmas weekend, as Omicron cases soared. read more The S&P 1500 airlines index (.SPCOMAIR)declined. Cruise operators Norwegian Cruise Line Holdings (NCLH.N), Royal Caribbean (RCL.N) and Carnival Corp (CCL.N)all fell, leading declines on the benchmark S&P 500. "The market is in this interesting place where we have a strong consumer, with spending up 8% year over year. Personal consumption makes up 70% of our GDP, and that remains flush," said Sylvia Jablonski Kampaktsis, chief investment officer and co-founder at Defiance ETFs in New York. "Omicron reminds us that we still exist in this corona ecosystem. And it"ll probably be one of many things that we will continue talking about with this virus but the doomsday COVID scenario of 2020 feels like it"s far behind us." Monday"s climb marks a fourth straight session of gains for Wall Street"s main stock indexes after encouraging news last week related to the Omicron variant eased worries about the strain"s economic impact. read more All 11 main S&P 500 sector indexes advanced, with energy (.SPNY) and tech (.SPLRCT) leading percentage gains. According to preliminary data, the S&P 500 (.SPX) gained 65.21 points, or 1.39%, to end at 4,791.00 points, while the Nasdaq Composite (.IXIC) gained 216.53 points, or 1.38%, to 15,869.90. The Dow Jones Industrial Average (.DJI) rose 350.63 points, or 0.98%, to 36,301.19. The Nasdaq Composite (.IXIC)got a boost from megacap companies, including Tesla Inc (TSLA.O), Microsoft Corp (MSFT.O), Apple Inc (AAPL.O) and Meta Platform (FB.O). Main U.S. stock indexes are on track for a third straight yearly gain, with the benchmark S&P 500 (.SPX) set for its best three-year performance since 1999.