Post #31319 1 Oct 17, 2026, 07:36 UTC StepFun Releases Step 5 Preview Open Weights: 600B MoE, 27B Active, 1M Contextvia MarkTechPost (author: Michal Sutter) Telegraph StepFun Releases Step 5 Preview Open Weights: 600B MoE, 27B … StepFun has released Step 5 Preview as open weights. FP8 and BF16 checkpoints are live on Hugging Face and ModelScope. Step 5 Preview is a sparse Mixture-of-Experts model from StepFun built for long-horizon agentic work. It has 600B total parameters, 27B…