Google announced Gemini 4 Argon on September 30, 2026, as its new flagship model anchoring the Gemini 4 generation, with initial limited access granted to select cybersecurity partners via the Fairwind Program. This followed months of delays and the decision to cancel the previously teased Gemini 3.5 Pro entirely after Gemini 3.1 Pro launched in February 2026. Argon emphasizes larger-scale capabilities for long-horizon reasoning, advanced coding, and cyber defense benchmarks, positioning it against frontier models from OpenAI and Anthropic amid ongoing post-training refinements and safety evaluations. Traders are monitoring signals for broader public API or app availability, which could occur in the coming weeks given Google's recent cadence of Flash and variant updates, though no firm timeline has been confirmed beyond hopes for release well before year-end.