Google's recent rollout of the limited-access Gemini 4 Argon model on September 30, 2026, has shifted attention away from the long-delayed Gemini 3.5 Pro, which the company confirmed it no longer plans to release. Argon represents the first public step in the Gemini 4 generation, emphasizing advanced coding, cybersecurity, and long-context reasoning benchmarks while undergoing phased deployment starting with trusted partners and safety reviews. Pre-training for the broader Gemini 4 family continues on Ironwood TPUs, with internal priorities on larger base models for agents and frontier performance amid competition from OpenAI and Anthropic. Leadership transitions at DeepMind and the absence of a confirmed public Pro-tier timeline introduce uncertainty around when a full Gemini 4 Pro equivalent might reach general availability. Traders are watching for any developer conference updates or earnings commentary on release windows.