Microsoft, Amazon, and Alphabet have reported strong growth in cloud computing revenues, but a new AI-related risk has emerged. Microsoft recently revealed that OpenAI now accounts for roughly 70% of its AI revenue and around 45% of its commercial backlog, creating significant customer concentration risk. Growth is coming primarily from two companies, OpenAI and Anthropic, which face structural problems, including cost disadvantages due to higher energy prices and the difficulty of maintaining a leading AI model. If these companies cannot sustain an advantage, their ability to sign large compute agreements could shrink, impacting future returns from AI investments. Microsoft is responding by positioning itself as a platform that routes queries across different models rather than committing to one, a strategy CEO Satya Nadella believes is right for the longer term. The article notes this approach may not work for every company in the AI ecosystem, and AI has been the major force driving stock market prices higher.