During the U.S. stock trading session on October 28, both Microsoft and Apple entered the $4 trillion market capitalization club. This marks the first time that Apple's total market value has exceeded $4 trillion. Since the release of its new product on September 9, Apple's share price has risen by approximately 13%, turning positive for the first time this year. Microsoft rose more than 3%, with its market capitalization once again surpassing $4 trillion. The company signed a new agreement with OpenAI, under which OpenAI will purchase an additional $250 billion worth of Azure services. At the current valuation levels, which company presents a better investment opportunity?