Physix Frontier · News Briefing Card (Leiphone · Oct 10, 2026)

Step 5 Preview Tops OpenRouter Trending, Open Source Oct 15

KEY FACTS

StepFun's flagship foundation model Step 5 Preview has claimed the No. 1 spot on OpenRouter's Trending list.
The model ranks second globally on OpenRouter's daily chart.
StepFun officially announced that Step 5 Preview will be open-sourced on October 15.
The model uses a sparse MoE architecture with 600 billion total parameters and roughly 27 billion activated parameters per token.
Artificial Analysis benchmarks show a composite intelligence index of 44, placing it in the global open-source top three.

KEY DATA

600 billionTotal Parameters

~27 billionActivated Parameters per Token

44Composite Intelligence Index

October 15Open-Source Date

PHYSIX OBSERVATION

StepFun pushed a 600-billion-parameter MoE model into the top ranks of both OpenRouter charts, showing that developers now weigh cost-effectiveness more heavily than raw performance. After the October 15 open-source release, if weights and inference costs are managed well, it could become a popular foundation for coding agents — competition among domestic open-source models is shifting from benchmark scores to real call volume.

Source: Leiphone report