The Rule of 72 Do you know how long it may take for your investments to double in value? The Rule of 72 is a quick way to figure it out. Share | Related Content 16 Wall Street Cliches in 60 Seconds Pundits say a lot of things about the markets. Let's see if you can keep up. All Muni Bonds Are Not Created Equal Gaining a better understanding of municipal bonds makes more sense than ever. Keys to Investing for Retirement There are some key concepts to understand when investing for retirement.