AI Frenzy Resurfaces: Bubble Anxiety and Capital Expenditure Debate Spurred by Micron's Earnings

Introduction

Just as global investors were feeling uneasy about lofty valuations, Micron Technology's blockbuster earnings last week injected a dose of adrenaline into the AI-driven stock market rally. This report not only showcased explosive demand for AI chips but also rekindled market enthusiasm for tech stocks. However, as the exuberance cools, Wall Street's concerns about an AI bubble are heating up again, sparking a fierce debate: Is AI a genuine productivity revolution or an overhyped capital feast?

Rise or Fall by AI?

Micron's Earnings: Rescue and Underlying Worries

Micron's earnings report was undeniably one of the most watched highlights in recent markets. The memory chip giant's results not only far exceeded market expectations but were also seen as a barometer of sustained strong demand for AI infrastructure. Its robust revenue growth and margin expansion seemed to validate that AI investments are translating into real financial returns. However, behind the impressive figures lie deep concerns about excessive valuations and the sustainability of capital expenditures.

According to Tom Essaye, founder of Sevens Report Research, although Micron's earnings grew significantly, its stock's P/E ratio remains around 10, roughly half that of the S&P 500. This valuation gap reflects investors' underlying worry that the AI boom may not last. Essaye further noted, 'If investors believe this trend will continue, and Micron's earnings reinforce that notion, then there is still significant upside in this market.' Such commentary both affirms the potential of the AI industry and highlights market fears of a bubble burst.

Capital Expenditure: A Bet on Faith or a Rational Choice?

However, the continued expansion of the AI industry heavily relies on nearly boundless capital spending by tech giants. According to analysis, the 'Magnificent Seven' plus Broadcom and Oracle saw a combined market cap loss of about $2.7 trillion in June, precisely because investors are worried about the sustainability of capital spending by these AI-funding companies. This data undoubtedly sent shockwaves through the market.

A recent study by the National Bureau of Economic Research (NBER) sounded an alarm. Surveying 6,000 business executives, about 90% said that AI 'has not had any impact on employment or productivity' in the past three years. Meanwhile, Deloitte data shows that only 10% of executives have seen actual returns from AI investments, and many believe it will take several more years to see results. These frontline observations present a stark contrast to Wall Street's optimistic vision of AI.

Nevertheless, some analysts believe that tech giants will not retreat due to short-term lack of returns. Jason DeSena Trennert, founder of Strategas, stated bluntly, 'To put it mildly, these valuations are indeed a bit stretched.' But he added, 'I think for the CEOs of these companies, the risk of not investing in this technology is actually greater than the risk of investing and losing money.' This view frames AI investment as a 'bet on faith'—not investing risks being eliminated in future competition, while investing, even at a short-term loss, may yield long-term rewards.

Echoes of History: Warnings from the 1990s Internet Bubble

Seth Bernstein, CEO of AllianceBernstein, offered a broader historical perspective. He acknowledged that AI is indeed one of the technologies that can change society, with eventual impact possibly exceeding the internet and roughly comparable to the invention of the printing press in the 15th century. However, he emphasized, 'Believing that a technology can change the world and believing it is an investment are two different things.'

Bernstein noted that in recent years, AI concept stocks, including chipmakers and 'hyperscale data center' companies like Microsoft, Amazon, and Alphabet, have seen tremendous gains. Yet some valuation metrics remain at historically high levels, suggesting that investors may have already priced in future earnings growth potential too early. When market expectations are as high as they are now, there is little room for error. History repeatedly shows that investors can pay a heavy price when high expectations are dashed.

Bernstein further said that the current situation has 'some real similarities' to the internet bubble of the late 1990s. He cited SpaceX's initial public offering (IPO) earlier this month as a good example. Though not yet profitable, its market cap briefly became the fifth largest in the world. Such phenomena were common during the internet bubble, when many unprofitable internet companies achieved staggering valuations based on future growth prospects.

At the index level, signs of a bubble also exist. A commonly used valuation metric for the S&P 500—the cyclically adjusted price-to-earnings ratio (CAPE)—has approached historical highs driven by the AI frenzy. This metric compares current stock prices to rolling average earnings over the past 10 years. Historical data shows that when the U.S. stock market CAPE exceeds 25 times, it enters a period of 'irrational exuberance.' Additionally, market concentration is extreme, both in terms of AI stocks' market cap relative to other markets and the U.S. stock market's share relative to the rest of the world, reaching historical extremes.

Bull vs. Bear: Two Voices on Wall Street

Facing the potential AI bubble, Wall Street opinions are sharply polarized. The pessimistic camp, led by AllianceBernstein's Bernstein, believes a market correction is nearly inevitable. He said bluntly, 'Why wouldn't you be worried?' He expects a pullback at some point. 'Could we have a substantial correction? I think it's very possible.' But he admitted, 'Can I tell you when it will happen? No. And it could take a long time.'

Besides high valuations, Bernstein's concerns also stem from external factors. He believes inflation is one of the biggest threats to the market. Tariffs, sustained government spending, and high oil prices could continue to push inflation higher. In such a macro environment, overvalued markets are more vulnerable to shocks, and any negative news could trigger a sharp sell-off.

However, there are also quite optimistic voices on Wall Street. Amanda Agati, Chief Investment Officer of PNC Asset Management Group, said, 'I think the natural tension lies in fundamentals and growth trajectory.' She does not believe the AI bubble is about to burst, instead viewing it as 'a continuous rally that shows no signs of weakening.' Agati's view represents investors who believe in strong AI fundamentals and sustained growth momentum. They argue that short-term valuation fluctuations cannot change the trend of AI as a long-term investment theme.

Conclusion: At the Crossroads of Frenzy and Rationality

Micron's blockbuster earnings undoubtedly injected new life into the AI rally, but did not fundamentally resolve market anxiety over a bubble. This debate about AI is essentially a deep reflection on the relationship between 'technological change' and 'capital pricing.' On one hand, AI's potential is enormous—it may fundamentally alter human production and lifestyle, much like the internet and the printing press. On the other hand, capital markets tend to excessively discount future expectations, creating bubbles. When expectations diverge sharply from reality, a bubble burst becomes inevitable.

For investors, this is undoubtedly a challenging era. They must find a delicate balance between faith in AI's future and caution about high valuations. Whether choosing to believe in tech giants' continued investment or to heed historical bubble lessons, one must recognize that AI development is still in its early stages, and its true impact on the economy and society may take years or decades to fully materialize. In this uncertain journey, maintaining a rational, prudent attitude and a full awareness of risks may be more important than blindly following market sentiment.

As AllianceBernstein's Bernstein said, 'Could we have a substantial correction? I think it's very possible. Can I tell you when it will happen? No.' In the days ahead, market volatility and corrections are almost inevitable. However, for investors who truly understand and believe in AI's long-term value, each correction may be an opportunity to reassess allocations and seize opportunities. The key is to find one's own path between frenzy and rationality.