Here at The Motley Fool, we talk about "buying on the dip" when we see companies we like but would prefer to see a pull-back before we buy in. In the following video, Fool contributor Matt Thalman discusses a few recent opportunities in which investors could have bought into a few different blue-chip stocks had they been following the market and noticed the opportunity. The old saying that you should buy low and sell high may be easier said than done, though, as a lot of investors lack the patience and discipline to wait for good buying opportunities, and some opportunities can simply be overlooked. With the speed at which a few recent shares came back after falling, it's easy to see why although dips do occur, the average investor may miss them.