xAI released Grok 4.7 on September 21, 2026, after repeated delays, establishing a pattern of rapid iteration with models shipping every 25–52 days once training completes. Elon Musk has positioned Grok 4.8 as the immediate successor—a 2.5-trillion-parameter model trained on a new C++ stack that was slated to finish pre-training in mid-September before entering reinforcement learning, with expectations of a noticeable capability lift over 4.7. Historical release gaps and ongoing Colossus cluster scaling point to an October–November window, though xAI’s track record of timeline slippage and competitive pressure from Claude and GPT-6 updates introduce uncertainty. Traders monitor Musk’s X posts and API documentation for the next confirmed launch.