DeepSeek’s dominant position in OpenRouter market share for the week of August 31 stems from sustained leadership by its V4 Flash models, which combine strong agentic and coding performance with pricing often 10-100x lower than U.S. frontier offerings. These open-weight releases have driven consistent developer preference for high-volume workloads, building on months of Chinese labs capturing the majority of routed tokens through cost and accessibility advantages. The market’s near-certain implied probability reflects this entrenched momentum and the absence of disruptive new releases in the period. A late-week surge from Tencent’s Hy4 or Z.ai’s GLM series, or an unexpected OpenAI discount extension, could still narrow the gap, though historical patterns make such shifts unlikely to overturn the weekly outcome.