Alphabet (GOOGL) begins October with a tremendously strong growth profile among the mega-cap tech companies, but investors are more and more concerned with the cost of that growth. Alphabet Class A shares ended trading on October 5 at $346.47, up 0.86% on the day, giving the company a market capitalization of approximately $4.24 trillion. Search remains strong and Google Cloud continues to post extraordinary growth, as does Gemini, but the growing risk is in the company’s infrastructure spending.

What is interesting is how Alphabet is no longer just trying to protect Search from disruptive AI. The company is using AI in a number of areas, including Cloud and Search as well as selling TPUs and enterprise software, while also spending at…