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 Emerging Market Opportunities What are your options for investing in emerging markets? Investment Challenges of the Affluent Investor Affluent investors face unique challenges when putting together an investment strategy. Make sure you keep these in mind. Saving for College This calculator can help you estimate how much you should be saving for college.