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 From Boats to Brokers From the Dutch East India Company to Wall Street, the stock market has a long and storied history. Four Really Good Reasons to Invest There are four very good reasons to start investing. Do you know what they are? 5 Smart Investing Strategies Getting what you want out of your money may require the right game plan.