Statistically, the stock market is the greatest wealth creator on the planet. We've observed the stock market do this just six times, spanning 155 yearsThere are always catalysts and historical precedents threatening to drag down equities. You'll also see the Shiller P/E referred to as the Cyclically Adjusted P/E Ratio, or CAPE Ratio. Despite being introduced by economists less than 40 years ago, the Shiller P/E Ratio has been backtested to January 1871. But as of the closing bell on July 27, the S&P 500's Shiller P/E Ratio was nearly 40.5.