纳指單日跌幅4.2%，「黑色星期五」戳破美股泡沫？

Original | Odaily Planet Daily (@OdailyChina)

Author | Qin Xiaofeng (@QinXiaofeng 888 )

On Friday, June 5, U.S. stocks experienced the sharpest single-day pullback so far in 2026. The Nasdaq Composite Index plummeted 4.18% to close at 25,709.43 points, marking its largest single-day drop since April 2025; the S&P 500 Index fell 2.64% to 7,383.74 points, ending a nine-week consecutive winning streak; the Dow Jones Industrial Average dropped 695.15 points (1.35%) to close at 50,866.78 points. The Philadelphia Semiconductor Index plunged over 10%, with a single-day market cap evaporation of approximately $1.3 trillion, led by AI core stocks such as NVIDIA, Broadcom, Micron, and Marvell.

Suddenly, the question of "Have U.S. stocks peaked?" spread from trading floors to screens of global investors. Odaily Planet Daily will conduct a rigorous analysis combining recent data and historical comparisons: Are current U.S. stock valuations too high? Is this pullback a healthy correction or a trend reversal? What are the future driving factors?

1. June 5 Crash Panorama: A Data-Driven "Perfect Storm"

The non-farm payroll data released on Friday evening was the direct trigger for this crash.

The U.S. Labor Department reported May non-farm payroll data, showing an increase of 172,000 jobs, nearly double the market expectation of 88,000 and significantly higher than April's 115,000. April's employment data was already above expectations. Furthermore, March's employment data was revised upward by 29,000, and April's data was revised upward by 64,000. The employment growth rate over the past three months has become the strongest in two years. This indicates that previous employment data systematically underestimated the strength of the U.S. job market, enough to fuel market concerns about an overheating economy.

The strong employment data pushed up inflation expectations, leading the market to anticipate the earliest possible Fed rate hike in October this year. Following the data release, U.S. Treasuries were sold off, with the yield on the 10-year note rising 5.8 basis points to 4.531%, and the policy-sensitive 2-year yield climbing over 7 basis points in a single day to 4.1%.

The jump in bond yields severely impacted tech stocks, which are high-valuation, high-growth assets most sensitive to interest rates.

Although Broadcom's earnings report the previous day was strong, its AI custom chip business guidance failed to meet the market's extremely high expectations, triggering a chain reaction. NVIDIA fell over 6%, Micron dropped 13.3%, Marvell slid 16.7%, and AMD declined 10.9%. Profit-taking concentrated in the semiconductor sector, combined with doubts about the sustainability of AI capital expenditure, created an avalanche effect. Meta reportedly plans to add tens of billions of dollars in AI investment, but this failed to reverse the sector's downturn.

Trading volume expanded, and the VIX volatility index surged 37% to 21.15, indicating a rapid spread of risk aversion sentiment. Bitcoin simultaneously fell below $60,000, while gold and crude oil also saw adjustments, putting broad pressure on risk assets. However, not all sectors declined: defensive sectors like utilities, healthcare, and consumer staples bucked the trend, with old-economy blue chips such as Johnson & Johnson and Coca-Cola attracting safe-haven flows. This suggests the market isn't in full-fledged panic but facing a targeted adjustment in high-valuation sectors.

On a weekly basis, the S&P 500 ended its nine-week winning streak, with the Nasdaq posting a weekly loss of 4.7%, its worst in over a year. The Dow was relatively resilient, falling only 0.3% for the week, indicating signs of sector rotation.

"This is an extreme case of 'good news is bad news,'" said Michael Wilson, Chief U.S. Equity Strategist at Morgan Stanley, in a post-market report. "Strong employment data means the Fed's tightening shackles will be fastened tighter. It directly shakes the only pillar supporting high U.S. stock valuations: the imminent expectation of rate cuts."

2. The AI Myth Fades: Dominoes of a Crowded Trade

If the non-farm data was the trigger, then the bubble and fragility accumulated within the AI sector itself were the highly explosive gunpowder.

Over the past 18 months, AI has been the sole narrative driving U.S. stocks to new highs. NVIDIA's market cap briefly exceeded $5 trillion, accounting for over 7% of the S&P 500's weight, while the entire AI ecosystem-related stocks approached nearly 40% of the S&P 500's total market cap.

However, entering the second quarter of 2026, cracks began to appear in this belief.

Several cloud service providers, in recent supply chain surveys, were revealed to be cutting some orders for NVIDIA's next-generation Blackwell Ultra chips, citing excessive inventory buildup and a much slower monetization pace for enterprise AI applications compared to infrastructure investment. Although NVIDIA's late-May earnings report still showed impressive figures, its revenue growth guidance has slowed for three consecutive quarters, and gross margins have shown signs of decline.

The previously extremely crowded long-tech mega-cap trade quickly turned into a stampede of liquidations under the interest rate shock. When the non-farm data triggered a rate spike, the appeal of holding these high-duration, high-valuation growth stocks suddenly diminished. Their fragile marginal buyers—leveraged quantitative funds and retail investors—were the first to break, triggering a chain reaction.

"The AI trade has shifted from FOMO (fear of missing out) to fear of being trapped," said Jeremy Grantham, renowned value investor and co-founder of GMO, who has long warned about inflated AI valuations. He has previously compared the current situation to the eve of the 2000 internet bubble, pointing out that many AI companies' revenues may struggle to support their current high valuations.

3. Valuation and Historical Comparison: Has the U.S. Stock Market Reached a Bubble Peak?

This pullback has sparked widespread discussion about whether the market has peaked because it occurs against a backdrop of multiple high valuation and sentiment indicators converging.

First, valuations are at historical highs. Before the June 5 pullback, the S&P 500's cyclically adjusted price-to-earnings ratio (CAPE, or Shiller P/E) stood at approximately 39.5 times, the third-highest level after the 2000 internet bubble and the 2021 pandemic easing period, significantly higher than levels before the 2007 financial crisis. The forward P/E ratio was also around 22.5 times, well above the long-term historical average of 15.8 times. The "Buffett Indicator"—the ratio of total U.S. stock market capitalization to GDP—briefly touched 237% in late May, far exceeding the "severely overvalued" zone (>120%) defined by Buffett himself. Any unexpected negative news could accelerate mean reversion.

Second, capital and sentiment are at extreme levels. The Bank of America Bull & Bear Indicator rose to 8.5 in late May, firmly in the "extremely bullish" territory, which is often considered a reliable contrarian selling signal. The American Association of Individual Investors (AAII) bullish sentiment was between 35% and 45% for most of May—optimistic but not reaching extreme euphoria. Retail investor margin debt remained near historical highs of around $1.3 trillion in April and May, indicating continued active use of leverage.

Meanwhile, "smart money" has shown signs of retreat: Berkshire Hathaway's first-quarter 13F report showed its cash and equivalents reserve at a historical high of approximately $397 billion, and the company continued to be a net seller of stocks in the second quarter; the ratio of insider selling to buying rose to a high level not seen since 2021 in May.

Third, technical indicators signaled key breakdowns. The S&P 500 not only fell below its short-term moving averages last Friday but also broke through the lower boundary of its recent uptrend channel. The index is currently facing a test of its 200-day moving average (around the 7000-7200 point range). Technical analysts like Jonathan Krinsky, Chief Market Technician at BTIG, pointed out that if the S&P 500 cannot quickly recover key support levels and subsequently loses the 200-day moving average, it would technically confirm a potential mid-term correction, with an adjustment range possibly reaching 10%-15%.

4. Bulls vs. Bears: Pullback, Correction, or Start of a Bear Market?

Facing the market pullback, Wall Street bulls and bears quickly took sides, engaging in a heated debate.

The bearish camp believes this could be the beginning of a bubble unwinding. Some strategists point to signs of "stagflation" risk in the U.S. economy—while the May ISM Manufacturing PMI rebounded to 54.0 (expanding from the previous month), inflation indicators remain sticky. They warn that corporate earnings growth may face downward revision pressure due to financing costs and demand uncertainty, and the current equity risk premium is at low levels.

Societe Generale's star strategist Albert Edwards, who holds a long-term cautious view, warned that the AI bubble resembles past tech bubbles and could involve capital misallocation and challenges for some companies, posing a significant risk of a correction for the Nasdaq.

The bullish camp, however, emphasizes this is a healthy, albeit delayed, adjustment within a bull market. Goldman Sachs Chief U.S. Equity Strategist David Kostin acknowledges valuations are high but believes the market, driven by earnings growth, still has support. He projects S&P 500 earnings per share to grow about 7% in 2026, with productivity gains from AI starting to improve corporate margins in the second half of the year. "The strong non-farm data precisely proves the economy isn't hard-landing; recession risk is extremely low. Once the interest rate panic subsides, capital will realize the solidity of the earnings base." Goldman Sachs maintains a relatively high year-end target for the S&P 500, having previously raised it to the 6900-7600 range.

UBS Global Wealth Management also advised clients to "buy the dip," citing healthy household and corporate balance sheets and the ongoing corporate stock buyback programs that will continue to provide a buffer for the market.

Liz Ann Sonders, Chief Investment Strategist at Charles Schwab, offered a balanced and pragmatic perspective: "'Peak' is never a point, but a process. Currently, the phase of broad-based rallies driven by liquidity and sentiment is over. We are entering a stock-picker's market driven by fundamentals. The overall market index may trade sideways and edge lower in the coming months, but we won't see a 2008-style collapse unless we witness a freeze in the credit markets."

5. Future Key Junctions: Inflation Data and the Fed's "Judgment"

Undoubtedly, two major events arriving this week will serve as the critical watershed determining the nature of this adjustment. On Wednesday, June 10, the U.S. May Consumer Price Index (CPI) will be released. The market generally expects core CPI to rise around 2.8%-2.9% year-over-year (April was 2.8%). If the data significantly exceeds expectations, it will strengthen market concerns about "inflation stickiness" and could push back expectations for a Fed rate cut further, thereby increasing pressure on both the bond and stock markets.

The Federal Open Market Committee (FOMC) meeting on June 16-17 will be a crucial observation window. Following the strong non-farm data on June 5, several Fed officials reiterated the need for caution. Officials like Cleveland Fed President Beth Hammack emphasized that while the labor market shows resilience, interest rates may need to remain at current higher levels for longer. The Summary of Economic Projections (dot plot) released then will be closely watched. If the median projection shows fewer rate cuts in 2026 than previously expected, or even hints at keeping rates unchanged for the entire year, the market's expectations for the rate path will undergo a significant restructuring.

Additionally, geopolitical and trade policy risks could introduce further uncertainty. The U.S. has previously implemented import tariffs and export controls on advanced semiconductors to strengthen domestic supply chain security and limit the outflow of key technologies. When tech stock sentiment is fragile, this ongoing policy direction could still have long-term impacts on the global AI supply chain and push up the core inflation rate, thereby compressing valuations for some companies.

Conclusion

Back to the initial question: "Have U.S. stocks peaked?" 

For investors, all the necessary conditions to confirm a major long-term peak—extreme valuations, policy shift, weakening core narrative, retail investor frenzy, technical breakdown—are appearing simultaneously for the first time in over a decade. Historical experience suggests that when these signals resonate highly, even if the bull market doesn't end immediately, the risk-reward ratio has already deteriorated significantly. The market is currently in a fragile transition phase from "narrative" to "reality." The long-term productivity promise of the AI revolution must begin to withstand the rigorous scrutiny of every macroeconomic data point and earnings report.

The era of betting unilaterally on an ever-rising market may be over. Caution is the simplest form of respect for risk. Over the next two weeks, investors need to watch every decimal point in the May CPI report and every potential shift in the Fed's dot plot. Together, they will determine whether this summer is a mere episode within a bull market or the beginning of a new era.