For the stock market, one popular valuation is the Shiller cyclically adjusted P/E ratio for the S&P 500 SPX +0.43% , which is now 23.2, vs. the pre-bubble average of about 15. It’s been higher on only three occasions in the past 93 years: Just before the 1929 crash, just before the 2000 crash, and just before the 2008 crash.
