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 A Brief History of Estate Taxes Federal estate taxes have long since been a lucrative source of funding for the federal government. Investments You’ve made investments your whole life. Work with us to help make the most of them. Understanding Marginal Income Tax Brackets An inside look at how marginal income tax brackets work.