It Was the Best of Times, It Was the Worst of Times All about how missing the best market days (or the worst!) might affect your portfolio. Share | Have A Question About This Topic? Name Email Address Message Thank you! Oops! Related Content Should You Invest in Exchange Traded Funds? There are hundreds of ETFs available. Should you invest in them? 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.