The immediate catalyst, it seems, is an intensifying focus on capex, or capital expenditures. Microsoft revealed that its spending surged 66% to $37.5 billion in the latest quarter, even as growth in its Azure cloud business cooled slightly. Even more concerning to analysts, however, was a new disclosure that approximately 45% of the company’s $625 billion in remaining performance obligations (RPO)—a key measure of future cloud contracts—is tied directly to OpenAI, the company revealed after reporting earnings Wednesday afternoon. (Microsoft is both a major investor in and a provider of cloud-computing services to OpenAI.)