OpenAI’s September 22, 2026 launch of GPT-6 Sol and GPT-6 Luna extended the capabilities of the earlier GPT-6 Astra model into faster, lower-cost tiers with 50% reduced API pricing and measurable gains in alignment, coding, and factuality. Luna targets high-volume tasks while Sol emphasizes deeper reasoning, positioning both ahead of prior GPT-5.6 variants and competitive with Anthropic’s Claude Opus 5.5 on select benchmarks. Rollouts continued through early October, expanding Luna access to free and Go users alongside an “Intelligent UI” feature. A late-September update referenced GPT-6.1 Sol, signaling continued iteration within the family. Upcoming catalysts include further ChatGPT integration, benchmark disclosures, and any competitive responses from rival labs that could shift developer adoption or market-implied odds on the next Luna release.