On a trailing earnings basis, the S&P 500 has been highly-priced above a 20x PE multiple (or below a 5% earnings yield) for most of the last two years. What does this suggest about future return potential, and perhaps more importantly, about the potential for negative returns? Although the absolute valuation of the stock market does impact future return potential, it has not been particularly useful in assessing the chance of losing money in the stock market.