CAPE: Does Nvidia Overstate Its Ominous Warning?

Michael LebowitzAdvisor Perspectives welcomes guest contributions. The views presented here do not necessarily represent those of Advisor Perspectives.

As equity valuations approach — or in some cases surpass — the record highs of 1999, investors are growing increasingly anxious. This unease is partly driven by the media issuing grim warnings, often based in part on CAPE valuations. For example, consider the following headlines and their summaries.

  • The AI valuation bubble is now getting silly - The Guardian (Oct. 8, 2025)
    • This article warns that concentration risk in the "Magnificent Seven" tech companies is at an extreme level. It notes the CAPE is at a dot-com bubble peak, and suggests that when the AI bubble bursts, there will be few places to escape the fallout.
  • ‘Extreme caution needed': Why the Wall Street Boom Might End in Bust - Yahoo Finance (Oct. 7, 2025)
    • This piece highlights that the CAPE ratio is more than double its long-term average, indicating potentially lower returns ahead. It points out that extreme valuations have historically led to periods of weak returns or sharp corrections.
  • Warren Buffett’s famed measure of stock valuations has entered dangerous territory - Business Insider (Oct. 1, 2025)
    • This article notes that the Shiller CAPE ratio is at its third-highest level ever. It cites Federal Reserve Chair Jerome Powell, who called the market "fairly highly valued," and highlights that 19 out of 20 Bank of America valuation measures are also historically elevated.
  • ‘We are in a gigantic price bubble': Famed economist warns extreme stock valuations point to negative returns ahead - Business Insider (Sept. 13, 2025)
    • Citing economist David Rosenberg, this report highlights the market's high CAPE ratio alongside a weakening economic backdrop, including a softening labor market.

The following graph shows the S&P 500 and CAPE since 1920. Given how the market performed after the prior two CAPE peaks (1999 and 1929), it should not be surprising to see fearful headlines like the ones above.

S&P 500 and Cape

CAPE levels are concerning. However, instead of assuming that the CAPE ratios of 1929 and 1999 are comparable to today, it is helpful to recognize how Nvidia and a few other big stocks are skewing the CAPE, and what that may mean for the rest of the S&P 500.