Check out the companies making the biggest moves in premarket trading: Novo Nordisk — Shares tumbled 10% after the Danish pharmaceutical company’s trial for Alzheimer’s disease failed to meet its main goal of slowing the disease’s progression. Tesla — CEO Elon Musk said on X that the company is close to finalizing its latest artificial-intelligence chip, A15, and is starting work on A16, sending the stock 2% higher. Musk said Tesla’s goal is to bring a new AI chip design to volume production every 12 months. Alphabet — The tech giant gained 3.5%. Alphabet was the only “Magnificent Seven” stock that was positive last week. Alphabet launched its latest AI model, Gemini 3 , last week. Alibaba — U.S.-listed shares of the Chinese e-commerce company jumped 4% after announcing its AI-app, Qwen, had 10 million downloads within its first week of launching. Oscar Health , Centene , Molina Healthcare — The health-care stocks all moved higher following a Politico report that the White House will include a two-year extension of the Affordable Care Act subsidies due to expire next month. The administration will also set new limits on eligibility, the report said, sources. Oscar Health soared 17.5%, while Centene rallied 8% and Molina Healthcare added 5%. Baidu — The Chinese internet stock rose more than 4% after an upgrade to overweight from neutral at JPMorgan. The bank cited an upcoming AI transformation for the company, and called for more than 60% upside ahead. MP Materials — BMO upgraded the rare earths miner to outperform from market perform, sending the stock up more than 3%. “We believe the current valuation represents an attractive entry point for investors looking to gain exposure to the rare earth thematic,” wrote BMO. Merck — The pharma giant rose 2% on the back of an upgrade from Wells Fargo to overweight from equal weight. The bank sees Merck filling the shortfall from the Keytruda expiration and said the company is entering a “catalyst rich period in the next 12-18 months.” Carvana — The used car retail platform added 3.3% following Wedbush’s upgrade to outperform from perform. Wedbush said its drop of around 13% in the last month is “overdone” and the stock has limited downside going forward. — CNBC’s Fred Imbert and Alex Harring contributed reporting.