OpenAI’s September 22 release of GPT-6 Sol and Luna—following GPT-6 Astra earlier that month—establishes the current cadence for the GPT-6 family, with 50% lower API pricing, improved inference efficiency, and stronger performance on coding and factuality benchmarks than the GPT-5.6 tier. This rapid succession of point releases, combined with direct competition from Anthropic’s Claude Opus 5.5 launch the same day, reinforces trader expectations that OpenAI will continue iterating on the Luna line. No official timeline exists for a 6.1+ variant, but historical patterns of quarterly or faster updates and the absence of confirmed delays point to OpenAI as the clear leader in market-implied odds for the next qualifying GPT Luna model.