Nobel Prize-winning economist Paul Krugman is looking at the current AI frenzy and getting some uncomfortable flashbacks. In his newsletter this week, he argued that what's happening now with artificial intelligence investments looks uncomfortably similar to the final stretch of the dot-com era, and that investors banking on the Federal Reserve to rescue falling tech stocks are setting themselves up for disappointment.

An Economy Running on Two Different Tracks

Krugman describes the 2025 U.S. economy as fundamentally "schizoid," pulled in opposite directions by competing forces. On one side, President Donald Trump has "abruptly reversed 90 years of U.S. trade policy" and "pushed tariffs to levels not seen since the 1930s," creating widespread "uncertainty" that's "depressing the economy."

But there's a counterweight: massive spending on "AI-related investment" that's currently "boosting the economy" even as other sectors slow down. The problem, according to Krugman, is that this AI boom "bears an unmistakable resemblance to the tech boom of the late 1990s," which didn't end with a dramatic crash but rather a long, painful deflation.

Why Monday's Rally Doesn't Mean What You Think

Here's where things get interesting. While economists and investors continue debating whether we're in an AI bubble, Krugman points to a specific pattern that should worry anyone paying attention: AI stocks are surging on rate cut hopes, and "these strong reactions don't make sense."

He highlighted Bloomberg's Mag 7 index, which had been sliding as AI bubble concerns mounted, only to suddenly "surge" on Monday when markets interpreted Fed commentary as signaling a higher probability of rate cuts.

"Some of us have seen this movie before," Krugman wrote. During the unwinding of the 1990s tech bubble, there were repeated "dead cat bounces" that looked exactly like this week's rally. Back then, investors believed in the "Greenspan put," the idea that former Fed Chair Alan Greenspan would ride to the rescue with rate cuts whenever stocks tumbled.

Spoiler alert: those rate cuts didn't stop the tech collapse. And Krugman is warning investors not to expect a Fed rescue operation this time either.

The Experts Can't Agree on Anything

The debate over AI's future has split prominent analysts and experts down the middle, creating genuine uncertainty for businesses and investors trying to navigate the landscape.

Treasury Secretary Scott Bessent dismissed bubble concerns entirely on Tuesday, arguing that the massive "AI build out" will expand into a broader industrial renaissance across the country.

Cathie Wood of Ark Invest also pushed back hard against the skeptics, insisting that "the AI story has just begun." She blamed recent market volatility on a temporary "liquidity squeeze" that will reverse within the next "few weeks."

But investor and author Ruchir Sharma sees reason for serious concern. He argues that the U.S. economy has become dangerously concentrated, warning that America is now "one big bet on AI." That kind of dependence on a single tech narrative, he suggests, creates profound structural vulnerabilities that could prove costly if the bet doesn't pay off.

The reality is that nobody knows for certain whether AI will deliver on its transformative promise or follow the dot-com path toward disappointment. What Krugman is highlighting, though, is that the market behavior right now looks awfully familiar to anyone who lived through the last tech bubble. And that's not exactly comforting.