Amazon became world's largest company by market capitalization, driven by AI infrastructure spending and capex acceleration.

Amazon topped the 2026 Fortune Global 500 this week, ending Walmart's 12-year run at the top of the list of the world's largest companies by revenue. Fortune credited record revenue growth and Amazon's massive bet on AI infrastructure as the key drivers behind the shift.

Amazon's revenue eclipsed $700 billion in 2025, a 12% increase that propelled it past Walmart, State Grid, UnitedHealth Group, and Saudi Aramco. The company plans to spend roughly $200 billion on capital expenditures in 2026, up from $131 billion in 2025, largely directed toward AWS and generative AI — positioning it at the forefront of a Big Tech AI capex race that analysts expect will exceed $700 billion across the largest hyperscalers this year.

Executive Chair Jeff Bezos, featured on Fortune's August/September cover, positioned Amazon's custom Trainium and Graviton chips as "the foundation upon which all of this AI sits" — a direct challenge to Nvidia and AMD's dominance of AI accelerator hardware. Amazon's next-generation Trainium4 chip is scheduled for release next year. The company has strategically structured its AI investments to feed its own cloud business: its roughly $25 billion investment in Anthropic came with a commitment from Anthropic to purchase more than $100 billion of Amazon's cloud services over time.

The shift in market sentiment has been striking. Bernstein analyst Mark Shmulik described AWS as being "in last place in AI" as recently as October 2025; by January 2026, he had named Amazon a top pick for the year. AWS revenue reached $37.59 billion in Q1 2026, up 28% year-over-year — its fastest growth in 15 quarters — with an operating margin of 37.7%, giving Amazon's capex spending a revenue growth narrative that not every hyperscaler can currently demonstrate.