Trader consensus has coalesced around a September 28 release for the next Claude Sonnet, reflecting Anthropic’s official launch of Claude Sonnet 5.5 today as the faster, lower-cost complement to the Opus 5.5 model introduced six days earlier. Confirmed announcements, immediate availability across Claude.ai and the API, and benchmark demonstrations of improved agentic coding and response speed have eliminated meaningful uncertainty for traders. Market-implied odds near 100% capture this verified timing rather than speculation. While the strong positioning rests on direct company statements, realistic challenges remain limited to last-minute rollout glitches or regional access delays that could technically shift exact availability without altering the announced date.