Mistral releases Mistral Large 4, nicknamed Le Chonk, a 1-trillion-parameter multimodal model

Reflection AI unveiled Beam, a text-only mixture-of-experts model with 501 billion total parameters and 23 billion active, pretrained on 23.8 trillion tokens with a 1-million-token context window. Reflection says Beam matches Z.ai’s GLM-5.2 on advanced reasoning benchmarks and beats leading Western open models while using 3-4x less inference compute (though it does not match the best open source models such as Kimi K3 or GLM-5.3). Weights and full technical details are due this month.

OpenAI published a large batch of mathematical results on October 6, 2026, produced by an internal frontier model that has not been released publicly. As of now, there are 719 manuscripts covering 372 topic families (groupings of related papers) on OpenAI’s public repository with the results, as well as formalizations in Lean for many of the proofs. There are also 10 summaries of the model’s reasoning, compute estimates expressed in ChatGPT Pro usage, and statistics on problems attempted.