**Musk’s September 14 announcement that Grok 4.8—a 2.5-trillion-parameter model trained on xAI’s new C++ stack—had finished pretraining and entered reinforcement learning remains the dominant driver of trader sentiment.** This followed the September 21 release of Grok 4.7 and aligned with xAI’s accelerated cadence of frontier models every 30–40 days. Historical gaps from Musk’s training-finished posts to public releases (25–52 days) point to an early-October to early-November window for 4.8, with traders closely watching RL completion, multimodal fixes, and any early benchmarks. Competitive positioning against Anthropic’s Opus-class and OpenAI models, plus xAI’s emphasis on engineering data and cost efficiency, further supports near-term expectations, though exact timing hinges on post-training evaluation and infrastructure scaling on Colossus.