OpenAI market share this week? Above 18.9%

If OpenAI scores above 18.9% on OpenRouter text market share by model author week of Sep 28, 2026, then the market resolves to Yes. This event will resolve based on 10:00AM ET Monday updated market share values reported by OpenRouter, rounded to one decimal place, for the week of Sep 28, 2026. If the named model author’s market share is not separately identified in the source chart, including if it is included in “Others,” all markets in the event will resolve to No. Kalshi is not affiliated, associated, authorized, endorsed by, or in any way officially connected with the governing benchmark. All trademarks, logos, and brand names are the property of their respective owners.