Get the entire 10-part series on Ray Dalio in PDF. Save it to your desktop, read it on your tablet, or email to your colleagues. With the S&P 500 index down 6.3 percent in August, many investors struggled to various degrees. Hedge fund managers such as David Einhorn, down 5.3 percent in August, and Lee Cooperman, down from 9 to 11 percent in his various funds, all found significant difficulty. What has surprised some is the degree to which normally noncorrelated fund managers, such as Cantab Capital and Winton Capital, have taken a dive in August as well. While they...