Google's Gemini 4 Argon, released in limited form September 30 and opened widely on October 13, drives the 69.9% implied probability by topping LMArena text Elo at 1525 and leading Vals Index economic-impact benchmarks with strong agentic coding, long-context, and multi-step reasoning results. Traders see this newest frontier model as the clearest current leader among closed labs, outpacing earlier September releases such as Anthropic's Claude Opus 5.5 and OpenAI's GPT-6 Astra on several practical metrics. Meta's Muse Wonder Full, launched October 12, adds late competition but lacks equivalent benchmark dominance so far. With resolution at month-end, any rapid follow-up releases or benchmark shifts could still alter the ranking before the final snapshot.