Check out the companies making the biggest moves midday: Wave Life Sciences — The Singapore-based biotech that trades on Nasdaq more than doubled, soaring roughly 140% , after posting positive interim data from a Phase 1 trial of an RNA obesity shot that cut fat but retained muscle. Paramount Skydance — The media company is launching a hostle bid to buy Warner Bros. Discovery after it lost out to Netflix in a bidding war. Shares of Paramount rose 7%, Netflix shares fell nearly 4%, while Warner Bros. stock popped 4%. In the wake of the news, Pivotal Research group downgraded Netflix stock. Structure Therapeutics — Shares of the biotech nearly doubled on Monday after the company said its obesity pill showed weight loss of as much as 11% after 36 weeks of treatment. Confluent – The Wall Street Journal published a report on Sunday that IBM is in advanced talks to seal an $11 billion deal to acquire data-infrastructure company Confluent, boosting the latter company’s shares by 29%. Broadcom — The chipmaker rose nearly 3% after The Information reported Microsoft was in talks of moving its custom chips business to Broadcom from Marvell Technology . Shares of Marvell shed 10%. Lumentum Holdings — The optical and photonic product manufacturer’s stock added 2% after it announced an extension of its strategic agreement with IQE, a British semiconductor company. Carvana , CRH — Ireland-based manufacturer CRH and automobile e-commerce platform Carvana will join the S & P 500, S & P Dow Jones Indices announced Friday. The changes will be reflected prior to the open of Dec. 22. CRH gained 6%, while Carvana rose nearly 12%. Berkshire Hathaway — Warren Buffett ‘s conglomerate announced the departure of Todd Combs , investment officer and Geico CEO, who will be joining JPMorgan Chase as head of the bank’s new Security and Resiliency Initiative to find direct equity investments. Berkshire also announced a few other structural changes before the legendary CEO steps aside at the end of this year. The stock fell more than 2% CoreWeave — Shares of the cloud AI company shed nearly 7% after announcing a $2 billion convertible debt offering. Five Below — The discount retailer rose more than 3% after Truist upgraded it to buy from hold. “Given the sustainability of the comps and upward earnings potential, we think the stock has much further to go on the upside,” the firm wrote about Five Below. — CNBC’s Liz Napolitano, Scott Schnipper, Itzel Franco and Yun Li contributed reporting.