Open-Source Models Decisively Overtook Proprietary in OpenRouter Market Share — 60-40 Ratio Inverted Over 90 Days as DeepSeek Leads With 16.3% of Token Volume

Analysis of OpenRouter API token consumption from March 19 through June 18, 2026 — covering roughly 6 trillion daily tokens across the top 10 labs — shows open-source models decisively overtaking proprietary in market share for the first time, inverting from a 60-40 proprietary lead to a 60-40 OSS advantage in 90 days. DeepSeek alone commands 16.3% of total token volume, with Chinese open-source models occupying six of the top ten slots; Tencent's Hy3 Preview grew from zero to near-parity with DeepSeek V4 Flash in a single month. The dataset excludes a Xiaomi free-tier promotion period in March-April to prevent skew, making the reversal a clean structural shift rather than a pricing artifact.