Much has been made lately about how the CAPE ratio — a popular valuation measure applied to the S&P 500 SPX, -0.24 — has ballooned to levels not seen since the dot-com bubble, and before that, all the way back to 1929. CAPE stands for cyclically adjusted price-to-earnings. It’s also known as the Shiller P/E ratio, named for the Yale professor who created it. While the metric has its share of critics, it’s still considered a standard measurement of market valuation. Aside from where it stands today, it’s safe to say that only twice before have we seen the CAPE ratio top 30. Both times, the bottom fell out of the market, as you can seen from this chart posted by Michael Batnick of the Irrelevant Investor blog: via