Been watching the fund manager sentiment shift pretty closely, and there's definitely something worth paying attention to here. The latest Bank of America survey just dropped data showing that for the first time in two decades, professional money managers are actually saying companies are overdoing it with capital expenditures. That's a pretty significant flip.

Here's what's interesting — since late 2022, roughly 90% of all S&P 500 capex growth has been tied to AI-related spending. We're talking about the usual suspects: Meta, Alphabet, Amazon, Microsoft. These hyperscalers have been throwing massive amounts of cash at AI infrastructure and data centers. But now the market seems to be reacting to a simple question: will all this spending actually generate returns?

The timing is worth noting too. This sentiment change happened within just the past three months, and you can see it reflected in how these mega-cap tech stocks have been trading. Most of them are down for the year despite the S&P 500 holding up relatively well. That divergence tells you something about where doubts are creeping in.

So what do you do if you're concerned about an AI bubble? The smart move might be to react by diversifying away from the concentration risk. Looking at the calendar of market performance, assets that have actually outperformed the AI crowd this year include international stocks, value-oriented plays, and bonds. Vanguard's recent outlook suggests these areas could have better risk-adjusted returns over the next five to ten years.

I'm not saying dump all your tech holdings tomorrow. Markets shift fast — one solid AI breakthrough and the narrative flips back. But if you're trying to hedge against the downside of an AI pullback, spreading capital into international equities, value stocks, and fixed income makes sense. It's about being thoughtful with your positioning rather than chasing the narrative of the moment.