An anonymous X account (@synthwavedd) claimed OpenAI has finished pretraining a base model codenamed Bel — successor to "Doug," reportedly over 10 trillion total parameters — expected to underpin the Astra family and a future GPT-6, and possibly an "AGI-threshold" system after further reinforcement learning. A Sept 13 follow-up claims early accounts have Bel outperforming GPT-6 Astra on coding tasks, and that OpenAI believes Anthropic lacks the compute to answer it before its stock listing.

Caveats: single anonymous source, secondary accounts disagree on basics (including whether Bel precedes or succeeds Doug), and OpenAI has made no public comment on Bel at all.