STORY: Stocks ended mixed Tuesday.The Dow fell eight tenths of one percent, while the S&P 500 rose four tenths to notch another closing high ... and the Nasdaq climbed nine tenths of one percent.UnitedHealth Group dragged down the Dow. The insurer’s shares plunged nearly 20% after the Trump administration proposed a very small increase in Medicare insurer payment rates. The plan was another woe added to the company’s disappointing revenue forecast for 2026. The stocks of peers Humana and Aetna-owner CVS also plummeted.Meanwhile, bellwether UPS rose fractionally after it projected higher revenue for 2026, also pulling up shares in rival FedEx which gained about two and a half percent.Later this week, megacap technology companies report results.Anna Rathbun, founder and CEO of Grenadilla Advisory says she thinks they will continue to boost the market though there could be some choppiness in the sector.“I am positive on the S&P 500. And I do think that it will be driven by technology, again, in some ways. I don't think it will be without volatility, because even among the large-scale tech players, AI players, there are things that are changing. So Nvidia for a long time was the winner in the AI race with its chip designing, AI chip designing capabilities. But then Google came out as a contender, and now Microsoft is making its own AI chips. So a lot of things are changing, even in the front of the winners of AI or perceived winners of AI. So that's going to be very interesting.”On the economy front, U.S. consumer confidence unexpectedly deteriorated in January, slumping to its lowest level since 2014. Also on Tuesday, the Federal Reserve began its two-day policy meeting with the central bank expected to announce no change in interest rates on Wednesday.Other stocks on the move included Corning, which surged 15.5% to a more than 25 year high after Meta said it would pay up to $6 billion for fiber-optic cables in AI data centers.:: General MotorsAnd shares of General Motors jumped nearly 9% after the automaker posted a rise in core profit on higher demand for SUVs and pickup trucks.