# AI Bubble or Revolution? The truth behind market concentration and investment trends. - **Source:** [The Big Picture](https://ritholtz.com) - **Published:** 2026-07-17 - **Topic:** [Finance](https://brifing.si/c/finance) - **Original article:** - **On Brifing:** https://brifing.si/s/4ae8ff8c-4b06-4ecb-af7c-9dae5b2d3561 ## History of Market Concentration The market dominance of large US companies declined between 1960-90 but rebounded after antitrust policies loosened in the 1980s. The so-called Magnificent 7 reached their current position through 846 mergers and acquisitions over the past 15 years. ## Global Comparison The US market share of top 10 companies is relatively low compared to many advanced economies where it ranges between 60-80%. Countries like Canada, France and South Korea show significantly higher corporate concentration levels. ## Dot-com Bubble Comparison During the 2000 tech bubble, Microsoft's P/E ratio was 60, while today it's below 20. Similarly, Nvidia's P/E ratio has returned to 2019 levels, aligning with earnings. These metrics suggest current conditions are more fundamentally sound than a bubble. ## The Nvidia Case Despite market cap fluctuations, Nvidia - often cited as evidence of an AI bubble - has maintained P/E ratios comparable to 2019 levels. Its earnings growth justifies its valuation, indicating AI investments aren't purely speculative. ## US AI Investment Leadership US private sector AI investments exceed China's by 20 times. Historically, overinvestment in new technologies (like railroads or fiber optics) initially caused losses but ultimately matured entire industries through consolidation. ## Lessons from History Most 19th century railroad companies failed, but survivors acquired infrastructure cheaply to build transcontinental networks. Similarly, Global Crossing's fiber investments failed but became foundational for today's internet giants. ## The Capital Misallocation Paradox While overinvestment in new technologies causes short-term losses, it drives long-term sector growth. As Dan Gross's 'Pop: Why Bubbles Are Great for the Economy' argues, this process fuels innovation and efficiency gains across industries. ## Conclusion: Revolution Not Bubble Data suggests current AI investments differ from the dot-com bubble, with stronger fundamentals and strategic importance in global competition. History shows technological revolutions consistently emerge through such capital allocation cycles. ## Sources covering this story - https://ritholtz.com/2026/07/overvalued-bubble-revolution/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._