A 600B Model for $1 per Million Tokens: StepFun's Step 5 Preview and the Price Collapse at the Frontier
StepFun released Step 5 Preview on 20 September — a 600B-parameter sparse MoE with 27B active per token, a 1M-token context window, multimodal input, and open weights promised for 15 October. It lands just below the frontier on benchmarks, at a fraction of frontier prices.
