You usually don't realize how good something is until it's gone. For most investors, the red-headed stepchild in their portfolios is cash. When markets are advancing, it's easy to see cash as a weak, underperforming asset that needs to be put to better use. After all, who wants sit on an asset earning low-single-digit returns when the markets are serving up double-digit gains? As a result, investments are made with less regard to the underlying fundamentals of the business.