The Rule of 72 Want to be Smarter With Your Money? Join our mailing list and get news and info to support your financial goals. First Name Last Name Email Address Thank you! Oops! 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 It Was the Best of Times, It Was the Worst of Times All about how missing the best market days (or the worst!) might affect your portfolio. Required Reading: The Economic Report of the President The Economic Report of the President can help identify the forces driving — or dragging — the economy. Keys to Investing for Retirement There are some key concepts to understand when investing for retirement.