The Junk Drawer Approach to Investing It's easy to let investments accumulate like old receipts in a junk drawer. 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. Keys to Investing for Retirement There are some key concepts to understand when investing for retirement.