The numbers come first.
Six companies that spent years in the valuation wilderness — posting flat share prices, thin margins and, in at least one case, getting shut down by its own parent — have collectively surged from a combined market cap of roughly $90 billion to almost exactly $1 trillion, as of the market close on July 21, according to Fortune senior editor-at-large Shawn Tully.
Tully, writing in Fortune on July 28, 2026, coined the term 'AI Centurions' for the group: GE Vernova, Vertiv, Seagate Technology, Western Digital, Sandisk and AppLovin. The label borrows from the Latin centum — 100 — because every member now carries a market cap above $100 billion and delivered annualized share gains of at least 100% over the measurement window.
From Underachievers to the Top 100
The starting line was mid-July 2023, when hyperscalers began planning large-scale AI data-center expansions. At that point, Seagate, Vertiv, Western Digital and AppLovin each sat between $7 billion and $14 billion in market value — well outside the top 300 U.S. companies by valuation. GE Vernova, spun off from GE in April 2024, began its public life at just under $40 billion. Sandisk, according to Fortune, separated from Western Digital in February of last year.
As of July 21, valuations in the group ranged from $114 billion (Vertiv) to $288 billion (GE Vernova). The median stock advanced at a 145% annual pace. For context, the Magnificent Seven averaged roughly 30% annually over the same period — meaning the Centurions compounded at more than quadruple that rate.
All but Vertiv now rank inside the top 100 U.S. companies by market cap; Vertiv stood at 101st. GE Vernova, Western Digital, Seagate and Sandisk are each currently worth more than Blackstone, Salesforce, Pfizer and Uber, Tully notes.
What Actually Drove the Surge
Four of the six — Seagate, Western Digital, Sandisk and Vertiv — sell directly into AI data centers: storage hardware and cooling systems, respectively. GE Vernova's giant turbines benefited from soaring power demand tied to the same infrastructure build-out. AppLovin is the outlier: an AdTech platform that exploits AI-driven gains in processing capacity to dominate mobile app marketing and monetization.
The underlying catalyst is a capital wave that Fortune describes as exploding from $35 billion in AI infrastructure spending in 2023 to a run-rate of $650 billion this year, with projections of $1.0 to $1.1 trillion in 2027.
The $900 Billion Question
Tully flags the obvious risk: the entire thesis rests on continued hyperscaler spending. The combined $900-billion-plus gain in market value accounts for roughly 3.5% of the rise in S&P 500 market cap since mid-July 2023 — a concentration that would amplify any reversal.
The market has already voted, and the verdict is clear: capital rewards companies that solve real infrastructure bottlenecks. These six did exactly that — not through government subsidy or regulatory preference, but by engineering products the hyperscalers needed and couldn't get elsewhere. That is free enterprise working as advertised. The risk, as always, is that valuations priced for a $1 trillion infrastructure cycle leave little margin for error if the spending plateau arrives sooner than the consensus expects. Investors who understand that distinction will read these balance sheets with both admiration and discipline.
