Stocks making the biggest moves premarket: Generac, Lennar, Nike & more

* Generac surges 33% on Amazon data center deal * Fluence Energy drops 22% after cutting guidance * Nike rises 1.5% on board appointment Generac jumped 33% after signing a $2.4 billion deal to supply Amazon with backup generators. Lennar fell 1.2% on weak Q3 earnings. Fluence Energy plunged 22% after slashing 2026 guidance. Nike gained 1.5% on a new board member. Arm Holdings rose 4% after CEO comments on demand.