ChatGPT's market share falls below 50% amid AI assistant competition

Amazon has completed its $50 billion investment in OpenAI by deploying the final $35 billion in two tranches over recent months, according to a securities filing released Friday. The investment, initially agreed to in late February, represents a major capital commitment from the cloud and e-commerce giant to the ChatGPT creator. The completion of the funding signals Amazon's continued strategic bet on generative AI capabilities.

OpenAI has outlined its approach to responsible AI governance in Europe, detailing safety, security, transparency, and provenance practices that align with regulatory requirements. The company is positioning these practices as supportive of the EU AI Act as it advances. The statement reflects ongoing industry engagement with European AI regulation.

OpenAI has cut prices on two models in its GPT-5.6 series: Luna by 80% to $1.40 per million tokens combined, and Terra by 20% to $14 per million tokens combined, while introducing a premium Fast mode for its flagship Sol model at double the standard price. The moves come days after Anthropic released Claude Opus 5 at competitive pricing and Google launched lower-cost Gemini models, signaling a shift in AI competition toward cost and speed rather than capability alone. Luna now competes directly with the market's low-cost inference tier, though it remains more expensive than some alternatives like DeepSeek's flash model.

Lilian Weng, a researcher who cofounded AI startup Thinking Machines Lab with former OpenAI CTO Mira Murati, is returning to OpenAI after announcing her departure from Thinking Machines earlier this week. The return marks a shift for Weng after her recent startup venture.