S&P 500 Industrials Hit Tech-Like Valuations on AI Infrastructure Boom

The S&P 500 industrials sector is trading at price-to-earnings ratios above 30, a level that rivals high-growth technology stocks and stands well above the sector's long-term average of approximately 20. The re-rating reflects a fundamental shift: after the chip phase dominated by Nvidia, the build phase has begun, and it requires steel, concrete, and electrical infrastructure.

The Physical Backbone of AI

While artificial intelligence is often framed as a software and semiconductor story, the physical requirements—power grids, electrical substations, cooling systems, and construction—fall squarely within the industrial sector. Corporate capital expenditure on AI data centers is reaching historic levels. Alphabet forecast its 2026 capex for AI infrastructure between $195 billion and $205 billion. McKinsey & Company estimates global spending on data centers could reach nearly $8 trillion by 2030.

"AI is a tech play, but nothing happens without the build out of the infrastructure. There's a whole backbone infrastructure that needs to be built, and that has really pushed up industrials," said Cinthia Murphy, director of research at VettaFi.

Jensen Huang, Nvidia's CEO, called it "the largest infrastructure buildout in human history."

Investor Money Follows the Build

Capital is flowing into the sector at pace. Over 60 industrials ETFs have seen approximately $23 billion in net inflows year-to-date in 2026. Individual winners reflect the trend: Caterpillar and GE Vernova have both risen over 50% this year, with Caterpillar up nearly 160% over the last two years.

Not every industrial subsector is benefiting equally. The Tema Space Innovators ETF (NASA) is down approximately 16.7% over the past month, suggesting investors are discriminating between AI-linked industrials and other themes. Meanwhile, Delta Air Lines shares have risen approximately 30-45% over the past year despite rising oil prices, reflecting broader confidence in industrial exposure.

Defense Spending Adds Fuel

Geopolitical instability is compounding the AI infrastructure story. Increased global defense spending is benefiting firms like Lockheed Martin and RTX Corp, creating a convergence between national security and industrial capacity. The dual tailwinds—AI buildout and defense—have shifted investor appetite toward traditional industrial firms that were once viewed as slow-growth value plays.

A New Valuation Paradigm

The implications extend beyond sector rotation. The AI boom has moved beyond the chip phase, where Nvidia dominated, into a build phase where physical constraints of the power grid and construction become the primary bottlenecks. This convergence of AI infrastructure and national security is creating a new valuation paradigm for old-guard industrial stocks, making them as expensive as tech stocks.

For investors, the question is whether these elevated multiples are justified by multi-year capex visibility or represent a cyclical peak. With $8 trillion in data center spending projected through 2030 and defense budgets rising globally, industrials may have shifted from value traps to growth proxies—at growth stock prices.