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 The Junk Drawer Approach to Investing It's easy to let investments accumulate like old receipts in a junk drawer. How Stocks Work Understanding how a stock works is key to understanding your investments. 5 Smart Investing Strategies Getting what you want out of your money may require the right game plan.