David Ellison, chairman and chief executive officer of Paramount Skydance Corp., center, outside the New York Stock Exchange (NYSE) in New York, US, on Monday, Dec. 8, 2025.Michael Nagle | Bloomberg | Getty ImagesThis is CNBC's Morning Squawk newsletter. Subscribe here to receive future editions in your inbox.Here are five key things investors need to know to start the trading day:1. One battle after another2. DC's AI movesNvidia H200 chips in an eight-GPU Nvidia HGX system.NvidiaTrump announced yesterday t ...