ChatGPT's market share has fallen from 60% to under 45% in just one year. DeepSeek has gone from zero to 7% market share in under 12 months. The trajectory is clear but the gap is still enormous. ChatGPT has 100 million daily users, a massive ecosystem of integrations, and the most recognized brand in AI. DeepSeek has cost advantage, open-source credibility and the backing of a Chinese government that wants to win the AI race. Will DeepSeek overtake ChatGPT by the end of 2026 or is OpenAI's lead insurmountable?
