🔬 research2026-09-21T00:00:00.000Z
StepFun Step 5 Preview: 600B Sparse MoE, 27B Active Parameters, and the Pareto Frontier for Agentic Coding
On September 18-20, 2026, StepFun released Step 5 Preview — a 600B-parameter sparse MoE model with only 27B activated per token, achieving 67.7% on DeepSWE v1.1, 33.3% on Terminal-Bench 4.0, and 99.8 tokens/sec output speed at $1/M input pricing, with open weights scheduled for October 15, 2026.
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