On November 18, 2025, Microsoft announced a major partnership with Anthropic, securing access to its Claude AI model for Microsoft Azure customers. The deal includes Anthropic committing to purchase $30 billion in Azure compute capacity and up to 1 gigawatt of additional compute, strengthening Microsoft's cloud and AI ecosystem. Microsoft's stock closed at $493.79 on November 18, down 2.70%, reflecting cautious investor sentiment despite the positive news. Some analysts noted that Microsoft's dual investments in both OpenAI and Anthropic could create competitive risks if Anthropic gains significant market share.