Z.ai holds the strongest position at 62% implied probability for third place on the Text Arena Math leaderboard by September 30, driven by its GLM-5.3-flash and max models ranking third in recent arena.ai lab aggregates behind Anthropic and Google. The August 2026 GLM-5.3 release delivered competitive math reasoning scores on benchmarks like MATH-500 and AIME variants while offering low-cost, open-weight deployment that supports broad evaluation participation. Alibaba and Moonshot sit further back at 17% and 5% respectively, reflecting solid but lower arena placement, while OpenAI, Meta, and others trade below 5% amid slower math-specific gains relative to frontier leaders. With resolution imminent, any unannounced model updates or voting surges in the final days could shift lab rankings before the cutoff.