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 What Smart Investors Know Smart investors take the time to separate emotion from fact. Best-Performing Asset Classes Bonds may outperform stocks one year only to have stocks rebound the next. 5 Smart Investing Strategies Getting what you want out of your money may require the right game plan.