The Stock Market Looks More Expensive Than Ever Before Based on Certain Measures, and Warren Buffett's Timeless Advice Has Never Been More Valuable

Over the last four years, the S&P 500 (SNPINDEX: ^GSPC) and Nasdaq Composite (NASDAQINDEX: ^IXIC) have been practically unstoppable in their continued march higher. Despite a number of potentially dislocating events, investors have bought into stock price pullbacks, pushing the indexes to new all-time highs this year. But as the bull market approaches its four-year anniversary, stocks, as a group, have never looked more expensive. Twenty-five years ago, as the dot-com bubble popped, Warren Buffett shared a simple metric he called "the best single measure of where valuations stand at any given moment." Today, that metric is hitting new record highs, indicating a severely overvalued stock market.