Tencent ships Hy4 preview, a 770-billion-parameter open model aimed at code and finance

On August 28, 2026, Tencent posted Hy4 preview to Hugging Face: a mixture-of-experts model with 770 billion parameters, only 49 billion of which activate per request, tuned for software engineering, research and finance. The headline is not the size — it is that open weights are now a distribution channel.