For the past two years, investors have experienced extraordinarily tumultuous times. From late 2008 through early 2009, stock markets in the United States and around the world have fallen sharply. The S&P 500 Index, a leading benchmark for the U.S. stock market, lost about half of its value, for example. As the winter of 2009 came to a close, stocks rebounded. For the remainder of last year and into early 2010, stocks enjoyed one of the strongest recoveries since the 1930s. Investors who held on recouped some of their losses, and those who rimed the market successfully had sharp gains. During the second quarter of 10, however, stocks dived again. Debt woes in Europe and sluggish employment growth in the