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. Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Content How Stocks Work Understanding how a stock works is key to understanding your investments. Bull and Bear Go To Market Learn about the difference between bulls and bears—markets, that is! Managing Money as a Couple Keys to preparing to grow wealthy together.