Microsoft Chairman and CEO Satya Nadella speaks in front of the OpenAI logo at the Microsoft Build conference in Seattle, Washington, on May 19, 2025.Jason Redmond | AFP | Getty ImagesThe $4 trillion club has a second member, at least based on after-hours trading. Following a better-than-expected earnings report on Wednesday, Microsoft shares jumped 8%, lifting the software giant's market cap to about $4.1 trillion. Should the rally stick on Thursday, Microsoft would join chipmaker Nvidia, which...