Analysts warn AI boom runs on unsustainable debt and insane hyperscaler capex spending; global regulators signal intent to restrict lending.

Stock market concentration among AI leaders has reached levels comparable to previous bubbles, according to Bank of America strategists. The "AI Big 10"—Nvidia, Microsoft, Alphabet, Amazon, Meta, Apple, Tesla, Broadcom, Micron, and Advanced Micro Devices—now account for 41% of the S&P 500, matching the concentration of technology and telecommunications stocks during the dot-com bubble.

The June jobs report and weak earnings from Nike underscore the persistence of a K-shaped economy, in which different segments of society experience sharply divergent outcomes. The upward trajectory benefits wealthy white-collar workers and asset owners who gain from rising stock and housing markets, while the downward path reflects low-wage workers, manual laborers, and small businesses facing prolonged financial stagnation, job losses, and declining living standards.

Jim Bianco, president of Bianco Research, sees this divergence continuing. "A lot of what's driving the top end is asset price gains. It's not just stocks, it's also real estate and other types of assets as well too. So as long as assets keep going up, this is an economy of do you own assets or don't you own assets? Do you own a home or do you rent? If you own a home and you have a portfolio, you're doing OK. If you rent and you're paycheck to paycheck, it's a different story."

Concerns about an AI bubble have intensified, though not all analysts see a repeat of the dot-com crash. Kenny Polcari, chief market strategist at Slatestone Wealth, argues: "This story is not the dot-com story. This AI zone that we're in is not what it was in late 1999, early 2000, when anyone would put a dot-com at the end of their name and suddenly had crazy valuations. While I'm a little bit concerned that valuations are stretched and I think in some names they are, I'm not in the camp that I think that this is a bubble that's going to burst the same way it did in 1999 and 2000, because these are real companies with real products."

The hyperscaler technology giants show no signs of slowing capital expenditure. Dan Ives, tech analyst at Wedbush, describes the situation as an arms race: "My view is that this is an arms race. And if anyone cuts back, others would just get ahead of them in line. It's about compute power. It's about capex. It's about building partnerships. They cannot, at this point, cut back because when you think about where we are in the AI revolution, they are right now going to be in the monetization phase over the next six, nine, 12 months."