Six old-economy stocks hit $100B+ valuations on AI boom

The emergence of the AI Centurions reflects a historic reset in manufacturing valuations. Three years ago, in mid-2023, these six companies occupied the underachiever category—Seagate and Western Digital had flat share prices over the prior decade, Vertiv's original franchise was axed by its parent for poor performance, and none ranked in the top 300 U.S. companies by valuation as recently as spring 2024. Their turnaround hinged not on financial engineering but on breakthrough products designed to solve concrete bottlenecks created by hyperscalers' rush to build AI data centers. Vertiv's water-cooling system, for instance, emerged from direct collaboration with Nvidia to understand what hyperscalers needed; Seagate's HAMR technology overcame physical limits to hard-drive capacity by using lasers during data writing. These innovations arrived at precisely the moment when demand for data center infrastructure became acute and supply could not keep pace.

The scale of value creation is striking: their combined valuation jumped from $90 billion to nearly $1 trillion, accounting for roughly 3.5% of the entire S&P 500's market-cap rise since mid-2023. On an annualized basis, their 145% median stock gain dwarfs the Magnificent Seven's ~30% return, and all six exceeded 100% annual gains—a cohort threshold that defines the "Centurion" label. As of July 21, 2026, four of the six (GE Vernova, Western Digital, Seagate, and Sandisk) rank in the top 100 U.S. companies by valuation, and Vertiv sits at the 101st position, all ahead of household names like Blackstone, Salesforce, Pfizer, and Uber.

However, their growth trajectory depends almost entirely on sustained expansion of AI infrastructure investment. The trajectory is steep: spending is expected to climb from $650 billion on a run-rate basis to $1.0 to $1.1 trillion by 2027. Their high valuation multiples—ranging from 29 for GE Vernova to 88 for Seagate—reflect market expectations for strong continued profit growth. Any material slowdown in data center spending or capex cycles could trigger sharp declines, since the premium prices these companies now command for their products (Western Digital's offerings have risen as much as 50% since the start of last year; Sandisk faces supply shortages raising prices faster still) rest on severe supply constraints and unlimited demand.