Should You Invest in Exchange Traded Funds? There are hundreds of ETFs available. Should you invest in them? 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. Mutual Funds vs. ETFs Exchange-traded funds have some things in common with mutual funds, but there are differences, too. 5 Smart Investing Principles Principles that can help create a portfolio designed to pursue investment goals.