OpenAI’s September 22, 2026 launch of GPT-6 Sol and Luna—built with methods similar to the earlier GPT-6 Astra—directly shapes trader views on the next 6.1+ Luna release. The models deliver 50% lower API pricing than GPT-5.6 counterparts through caching and inference gains, improved alignment and coding benchmarks, and phased rollouts that reached paid ChatGPT Work and Codex users immediately, free/desktop users by early October, and broader Chat access shortly after. Competitive pressure from near-simultaneous Anthropic releases and OpenAI’s own rapid iteration within the GPT-6 line reinforce market consensus that OpenAI will control the subsequent Luna update, with key near-term catalysts including further rollout milestones, benchmark disclosures, and any announced 6.1 variants.