Claude 4.8 released by July 31?

Anthropic shipped Claude Opus 4.8 on May 28, 2026 — more than two months before the July 31 deadline on the Polymarket contract. The announcement post is live, the API model string claude-opus-4-8 is active, and availability has been confirmed across Anthropic's platform and third-party cloud providers including AWS. The outcome is not in question. What makes this contract interesting isn't the resolution — it's the lag. If the YES side is trading at anything below the high 90s, that gap is pure market inefficiency: either the contract hasn't been flagged for resolution yet, or participants haven't updated on the May 28 announcement. Both are common in prediction markets that cover technical release events, where the information is public but dispersed. The Opus 4.8 launch itself is substantive. Anthropic positioned it as an upgrade to the Opus class with stronger performance across coding, agentic tasks, and professional work, and priced it identically to its predecessor. The release also introduced dynamic workflows in Claude Code — allowing hundreds of parallel subagents in a single session — and an effort control letting users dial how much compute the model applies to a given task. For a "released by" contract, none of that detail changes the resolution. The model is out. The market should reflect it.