The Shiller 10-year PE ratio is currently around 39.2 as of November 15, 2025, and the market is the second most expensive in history!  

The Shiller 10-year PE ratio (also known as the CAPE ratio), developed by Robert Shiller, is calculated by dividing the current price of the S&P 500 by the average inflation-adjusted earnings over the past 10 years. It smooths out earnings fluctuations and is used to gauge whether the market is overvalued or undervalued relative to historical levels.

Right now, the CAPE ratio has climbed to around 39-40, making the market extremely expensive compared to historical standards. A higher ratio such as this generally indicates overvaluation and predicts lower future returns, while a lower ratio would suggest undervaluation and higher potential future returns.[lynalden +2].

To put this in perspective, the long term average is closer to 16-18, so today’s levels are more than double historical average. It means that you’re paying a high price in the market

When the Shiller 10-year PE show values around 35.2 to 39.2, thus indicates a relatively high market valuation compared to historical averages. Historical data from Shiller has shown that when this ratio is high, subsequent long-term returns on the stock market tend to be lower than average.