Physix Frontier · News Briefing Card (TMTPost · Oct 1, 2026)

StepFun Releases Step 5 Preview, Ranks Second in Open Source but Misses Top 10 in Usage

KEY FACTS

On September 20, StepFun released Step 5 Preview, supporting text and visual input for coding and agent tasks.
On the third-party leaderboard Artificial Analysis, the model scored 44 on the intelligence index, tying with Kimi K3 for second among open-source models.
After Xiaomi released MiMo-V2.6, Step 5 Preview fell to third among open-source models.
As of September 27, Step 5 Preview was not in OpenRouter's weekly top 10 for usage.
StepFun's 2025 revenue is about 500 million yuan, projected at about 1.2 billion yuan for 2026, with no breakdown of revenue sources.

KEY DATA

44 pointsArtificial Analysis Intelligence

58 pointsClaude Opus 5.5 Score

ThirdStepCodeBench Ranking

About 500 million yuan2025 Revenue

PHYSIX OBSERVATION

StepFun's model capabilities have reached the threshold of the top open-source tier, but usage and revenue structure have not kept up. Leaderboard rankings are easily displaced by new models, while developer habits are harder to shake. Before going public, it needs to prove that at least one business line can generate renewable revenue; otherwise, the valuation gap will be difficult to narrow.

Source: TMTPost report