The U.S. stock market is approaching a valuation milestone not seen since the dot-com era, reviving questions about whether investors should brace for a repeat of one of Wall Street's most painful downturns.
The S&P 500's Shiller price-to-earnings ratio, also known as the cyclically adjusted P/E or CAPE ratio, recently reached 42.2, according to a report from The Motley Fool. That is the highest level in more than 26 years and puts the closely watched valuation measure within striking distance of its November 1999 record of 44.2.
