AI Debt Fears Sink Nasdaq, Chip Stocks Slide

The Nasdaq Composite fell roughly 2.5% on Friday, leaving it down almost 5% for the week and on track for its worst week since June. The S&P 500 dropped 1.4%, pushing its weekly losses past 2%, also its worst week since June. Investors weighed higher interest rates, mounting AI-related debt and risks to technology companies. They didn't like what they saw.

Both indexes had hit record highs just 10 days earlier. Since then, borrowing costs have weighed on debt-dependent corners of the AI boom, with pressure focused in one place: the neoclouds. These companies rent computing power to AI businesses, and they've relied heavily on borrowed money to do it.

The Debt Problem

CoreWeave, a neocloud backed by Nvidia that went public in 2025, carries tens of billions of dollars of debt on its balance sheet to finance its growth. Its bond yields recently climbed to levels signaling distress or a higher risk of default. That's a sharp reversal for a company once cast as the decade's picks-and-shovels play.

"It's unclear that (CoreWeave is) going to get a sufficiently good return to pay down the debt that they borrowed," Gil Luria, head of technology research at D.A. Davidson, told CNN. "As people get concerned about the trajectory of the buildout, they are the subprime tranche of the AI trade, and that's why they're selling off first."

Luria stressed that AI demand is real and growing. In his telling, though, real demand doesn't square with financing that looks unsustainable at steep interest rates. Both things can be true, and right now the market is pricing in the second one.

Nvidia CEO Jensen Huang told Bloomberg on Thursday that he was optimistic about CoreWeave, and the company's shares rallied that day. The gains didn't last. CoreWeave fell 14% on Friday, lost one-quarter of its value during the week, and sat more than 60% below a peak it had reached shortly after its March 2025 initial public offering. A CEO's endorsement, it turns out, can't outrun a balance sheet.

Chips Take the Hit

The semiconductor index fell 3.9% on Friday, marking its eighth consecutive daily decline. Investors had pushed chip stocks higher this year on expectations of a large AI buildout and chip shortages that could produce substantial profits. Now they're reconsidering the math. Higher costs and the possibility that political disputes over data centers could hurt growth forecasts have knocked the sector back.

Chinese memory-chip maker CXMT added to the pressure earlier in the week, announcing progress on advanced memory chips. Investors had counted on U.S. and South Korean chipmakers to hold dominant market share and pricing power. They're now asking whether cheaper, efficient Chinese chips could erode that position.

"The market sells first, asks questions later," said Thomas Martin, portfolio manager at Globalt Investments. The semiconductor index remains down more than 20% from its June peak, though it's still up almost 60% year to date. South Korea's benchmark Kospi, heavily weighted toward chipmakers SK Hynix and Samsung Electronics, fell 14.5% during the week, its worst weekly performance since 2008. It climbed as much as 116% year to date in June, then erased all its gains from the previous six months before settling 35% higher for the year.

Semiconductor companies account for roughly one-fifth of the S&P 500's market value, so the sell-off reaches well beyond a few speculative names. Wall Street's fear gauge, the VIX, jumped 30% on Friday to above 20 points, signaling elevated volatility.

The Spending Question

A New York Times DealBook analysis said the largest technology companies would spend around $800 billion on AI infrastructure in 2026, with consensus forecasts above $1 trillion for 2027. Goldman Sachs said that would represent a larger share of gross domestic product than any investment cycle since the railroads. Washington has made AI a national priority, raising an obvious question: could companies do the buildout for less?

Nvidia's gross margin in the previous quarter was 75%, while Micron, which sells memory chips, reported a margin of nearly 87%. Three years ago, Micron was losing money on memory chips. High margins usually attract competitors and bring prices down, but DealBook noted that competition has not yet compressed margins in the AI buildout, a signal visible since 2023. AMD, custom silicon from Amazon and Chinese open-weight models could eventually lower costs, the analysis said, though that will take time. Spending is already underway, partly with tax credits.

Federal Reserve Chairman Kevin Warsh suggested he wouldn't push to raise borrowing rates this month, though persistent inflation could force the Fed's hand. DealBook said the S&P 500 appeared set to open higher on Friday, largely because of Warsh's comments. The market's afternoon reversal suggests reassurance from the central bank only goes so far.

Why This Matters:

The sell-off is a reminder that private capital, not government mandate, decides which AI bets survive. Companies like CoreWeave borrowed heavily to chase growth, and now the bond market is repricing that risk in real time. Investors who lent against an unproven return profile are discovering what that exposure looks like when rates stay high. For taxpayers and pension funds with indirect exposure through index funds, the concern is concentration: semiconductors make up roughly one-fifth of the S&P 500's value, so a correction in one sector can ripple across the broader market. Spending figures approaching $1 trillion also raise fiscal and sovereignty questions about how much of the buildout depends on tax credits and national-priority designations rather than sustained customer demand. The episode tests whether market discipline can work through the AI cycle without a bailout, and whether capital will keep flowing to companies that can show they can pay it back.