Current CAPE or Shiller PE Ratio for the S&P 500, which is the average inflation-adjusted earnings from the previous 10 years stands at 30.30 times. Market Complacency Worrying Robert Shiller As per billionaire investor Howard Marks , "the Shiller Cyclically Adjusted PE Ratio, known as the Shiller CAPE, is at its highest level since only two other times in the market's history." Just before the Great Depression in 1929, and mid-1997 to mid-2001 saw the CAPE ratio at higher levels than we are in now.