Bubble or Revaluation: Analysis of the Logic Behind the Current US Stock Rally
Since 2023, the US stock market has staged a strong rally led by AI concepts, with the S&P 500 repeatedly hitting record highs and the Nasdaq surging dramatically driven by tech stocks. Faced with this notable rise, market participants and academics have been sharply divided: is this another asset bubble fueled by technological frenzy following the internet bubble, or an asset revaluation triggered by changes in the US economic fundamentals and global capital landscape? The answer to this question not only concerns investors' asset allocation but also profoundly influences the judgment of the future direction of the global economy.
I. The AI-Driven Technological Revolution and Bubble Concerns
On the surface, the core driving force behind the current US stock rally is undoubtedly the breakthrough in AI technology. The emergence of large language models represented by ChatGPT has ignited the market's boundless imagination for AI commercialization. Leading companies in AI infrastructure and applications, such as NVIDIA, Microsoft, and Google, have seen their stock prices soar, driving up the overall valuation of the tech sector. Historically, every major technological innovation has triggered capital market frenzy: the internet bubble of the late 1990s and the railway investment boom of the early 20th century were all accompanied by excessive optimism and speculative capital inflows.
Some characteristics of the current market do resemble the bubble period. On one hand, a handful of tech giants have contributed the majority of the index's gains, with market concentration at historical highs. On the other hand, valuations of AI startups are extremely high, with some companies that have not yet achieved stable profitability receiving P/E ratios dozens of times higher than traditional industries. More importantly, there is a lot of “storytelling” hype in the market, with funds chasing even companies only loosely related to AI. This “herd effect” is a typical psychological mechanism in the early stages of bubble formation.
However, bubble theorists must face a fact: the foundation of this rally is fundamentally different from the internet bubble period of 2000. Many internet companies back then lacked viable business models, while current AI leaders have demonstrated strong profitability and cash flow generation capabilities. NVIDIA's chip sales, Microsoft's Copilot subscriptions, and Amazon's cloud AI services have all translated into real revenue growth. Technology is being implemented much faster than 20 years ago, so although the weight of “expectations” in current valuations is high, it is not entirely baseless.
II. The Logic Supporting US Asset Revaluation
In contrast to the bubble theory, another view holds that the current US stock rally reflects a systemic revaluation of US assets. This argument is rooted in profound changes in the global economic landscape. On one hand, the Fed's aggressive rate hike cycle since 2022 did not trigger a recession as expected; instead, boosted by the AI investment boom, productivity has improved and the job market has remained resilient. The “soft landing” or even “no landing” scenario of the US economy has significantly lowered investors' risk premium requirements for US assets.
On the other hand, structural shifts in global capital flows are also supporting the repricing of US assets. Factors such as increased geopolitical risks, China's economic slowdown, and the European energy crisis are prompting international capital to allocate more to the “safe haven” US market. Although the US dollar's status as the global reserve currency faces challenges, there is no alternative in the short term, allowing the US to attract global savings at low cost to support its technological progress and fiscal expansion. From this perspective, the high valuation of US stocks is not purely speculative but a monetary manifestation of the relative improvement in US competitiveness in the global economy.
Another important support for the revaluation logic is the transformation of the industrial structure. Traditional valuation models are based on the industrial economy era, but AI, as a general-purpose technology, is disrupting traditional pricing frameworks in how it creates value. Asset revaluation means the market begins to recognize the high growth and sustainability of future cash flows for AI companies, thus willing to grant higher P/E ratios. If AI can truly boost total factor productivity, then current seemingly high valuations may be reasonable or even undervalued in the face of future earnings growth.
III. Historical Lessons and Future Direction
Looking back at history, every major technological change has been accompanied by intertwining bubbles and revaluations. The radio craze of the 1920s bred a lot of speculation but also gave birth to future industry pillars like General Electric and RCA; the internet bubble of the 1990s burst, but survivors like Amazon, Google, and Microsoft eventually became world-changing giants. The key difference: when the bubble bursts, those “fake innovation” companies without solid technology and business models disappear, while truly revolutionary enterprises continue to grow stronger after the pain.
The current US stock rally looks more like a “selective bubble.” Market enthusiasm for AI-related assets has some rationality, but there is indeed local overheating and pricing distortions. For investors, the most dangerous thing is not a systemic crash but excessively high expectations for short-term performance under high valuations. Once technology implementation falls short of expectations, it may trigger a sharp correction. The uncertainty of the Fed's future monetary policy path, the aftermath of the US fiscal deficit, and geopolitical risks are all external factors that could pop the local bubble.
Conclusion
Overall, the current US stock rally is neither a pure AI bubble nor a simple asset revaluation, but a complex interaction of both. Structurally, AI technology indeed represents the frontier of productivity improvement, and leading related companies have long-term growth value, which constitutes the legitimacy of asset revaluation. However, driven by sentiment, the market's pricing of AI already includes a lot of optimistic expectations, with obvious speculative colors in some areas. A reasonable judgment is that core US assets are undergoing a structural revaluation driven by technological revolution, but the process is accompanied by intermittent bubble characteristics. For rational investors, the key is to distinguish which companies can convert technological dividends into sustainable profit growth and which are merely dust in the bubble. Maintaining a balance between trend confirmation and risk control might be the best posture to deal with this “revaluation rally.”
