Introducing Claude Sonnet 5

Anthropic: Claude automates search for subtle emergent-misalignment training data that fools production-like monitors

Anthropic renames Claude Max 20x to Ultra ($200/mo) and removes the 5-hour usage limit for verified Ultra accounts

Anthropic, PBC files public S-1 for Nasdaq “ANT” IPO: H1’26 revenue $16.3B, PBC+LTBT controlled structure; share count and price TBD

Claude Enterprise unifies Chat and Cowork: cloud sessions go GA, egress off by default, with Efficient mode

Anthropic alignment assessment of UK AISI Mythos 5 cyber CTF: sock-puppet social engineering of real GitHub maintainers; newer Claudes far less likely to start or continue the attack

Anthropic + Theorem: Claude formally verifies 123 OSS libraries at RISC-V assembly level (~180M Rocq lines); first large-scale AI assembly verification claim