Check out the companies making the biggest moves in premarket trading: Boeing — Shares jumped 4% after the aircraft maker reached a deal with a union that represents its factory workers, potentially avoiding a costly strike. MarineMax — Shares jumped 6% after Citi upgraded shares to buy from neutral. The firm highlighted the upside of a lower-rate environment and limited downside risks. Palantir Technologies , Dell Technologies — Shares of Palantir and Dell rallied 8% and 5%, respectively, after it was announced postmarket Friday that the stocks would join the S & P 500 index. Palantir will replace American Airlines , while Dell will replace Etsy . Merck — The pharmaceutical stock dipped 2% after rival Summit Therapeutics announced phase three trial results for a lung cancer drug. Summit said that its product achieved a “clinically meaningful benefit” compared to Merck’s Keytruda. Summit shares soared more than 30%. Arm Holdings — The chip stock moved nearly 3% higher following a Financial Times report that Apple will use Arm’s artificial intelligence chip technology in the iPhone 16, set to be unveiled Monday. United States Steel — Shares moved about 3% higher after JPMorgan upgraded the industrial stock to overweight from neutral. The firm believes the recent pullback signals a buying opportunity on valuation support and expects shares to pullback even more if its planned sale to Nippon Steel falls through. JetBlue Airways — Shares gained 2% after Bank of America upgraded the airline stock to neutral from underperform, and hiked its price target, citing improving conditions such as falling fuel prices. The rating change also comes after JetBlue last week hiked its third-quarter revenue estimates. — CNBC’s Jesse Pound, Hakyung Kim, Sarah Min and Sean Conlon contributed reporting.
