5 Smart Investing Principles The slideshow presentation that you would like to view is too large for your current screen resolution. Click here to view to view the slideshow at full resolution. Launch Presentation » Share | Related Content 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. 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.