The first model class trained at scale on Blackwell arrives mid-handoff

Claim

Mythos appears to be the first model class trained at scale on Blackwell hardware with Vera Rubin waiting, a generational handoff occurring while pre-training still has headroom and fresh compute is only beginning to land, as OpenAI finalized its own staggered rollout of a cyber model to selected partners.

Reporting date: 2026-04-09 (not necessarily the event date)

Sources

Attribution and reporting linked by this record; links do not imply independent verification.

• Welcome to April 9, 2026 (theinnermostloop.substack.com)