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.

As of October 4, the name "Bel" still appears nowhere in OpenAI's model docs, API changelog, or news feed — a grading page from CellCog traces the whole claim back to one August 25 X post from @synthwavedd about a finished pretrain with 10T+ parameters, a successor to an earlier run codenamed Doug (which SemiAnalysis referenced in a July 9 subscriber note). The viral "GPT-6 Bel beats Astra" headline added a benchmark claim the source never made.

The same account said on September 23 that Bel is still months from going public. One thing to watch: OpenAI's Codex lead teased a release next week on October 3 without naming a model — if that materializes, the rumor may finally get a verdict.