Stock market bubble warnings grow louder
By Matt Egan Some of the brightest minds in finance are sounding the alarm about a stock market bubble. They aren't warning of an imminent crash, but their comments should remind investors that the current bull market -- over five years long -- can't last forever. 1. Nobel Prize-winning economist Robert Shiller: Valuations at "worrisome" levels. "The United States stock market looks very expensive right now," Robert Shiller wrote in a recent column for The New York Times . Shiller, a Yale University professor who is often cited as one of the most influential people in economics and finance in the world, created a metric that compares stock prices with corporate profits. The metric recently climbed above 25. That level has only been surpassed three times since 1881: 1929, 1999 and 2007. Steep market tumbles followed each instance, including the bursting of the dotcom bubble in the early 2000s. The Nasdaq still hasn'...