xAI's rapid iteration cadence and Elon Musk's September updates on Grok 4.8 training are the main drivers of trader sentiment. Grok 4.7 shipped September 21 after roughly five weeks of post-training on a larger base, quickly establishing leadership on coding benchmarks like CursorBench and VulcanBench plus cybersecurity and legal agent evaluations. On September 14 Musk stated the 2.5-trillion-parameter Grok 4.8, trained with a new C++ stack, would finish pre-training that week and begin reinforcement learning. Historical spacing of 35–40 days between recent releases and ongoing references to “Grok 4.8 when that comes out” point to a likely November–December window, with Grok 5 positioned further out as the AGI milestone. Competitive pressure from Claude Opus 5.5 and GPT-6 models adds incentive for xAI to maintain momentum.