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? Address Thank you! Oops! Related Contents Should I Invest in Gold? Learning more about gold and its history may help you decide whether it has a place in your portfolio. Mutual Funds vs. ETFs Exchange-traded funds have some things in common with mutual funds, but there are differences, too. Keys to Investing for Retirement There are some key concepts to understand when investing for retirement.