One of these stocks is not like the others.It's best to buy stocks when they are down, as one of the most famous investing maxims tells us: "Buy low, sell high." However, companies going through a rough patch on the market aren't automatic buys. It's essential, as always, to separate the wheat from the chaff. Though broader equities have been performing well for most of the year, there are enough beaten-down stocks to choose from these days.Let's discuss three of them: One that looks attractive is CVS Healt ...