I find it interesting that punditry is alive with the phrase, "It's a healthy correction."  There is more to this inanity than meets the eye. Sure, it is easy to say it's healthy after it happens, especially when you remained long throughout the whole thing. Talk your book much?

What is more profound is that it is a correction. By definition, corrections are interruptions in an ongoing trend. Therefore, if you call it a correction you must believe that the next leg will be to the upside. If you call it a correction then you are a bull. And if you are a bull you need to put your money where your mouth is and buy something. If you don't, then you are disingenuous. 

When a stock such as Microsoft drops about 12% after a stellar performance in 2017 then is that a good stock to buy "on sale?"  Check out the chart.

The first question to ask is "what's the trend?" The answer is "up."

The next depends on your favorite indicators. For me, supports and trendlines (not drawn) remain intact.

So, is this a strong stock that got whacked with a correction? It sure looks that way.

What about Procter & Gamble? It got smashed last week, too, but what was its trend before?

Looks rather stinky. The sell-off with the rest of the market actually broke serious support. Right now, if you think this is a good stock to scoop up at lower prices it should be because you see something else to like. The market correction is not what creates value here.

Here's one that looks similar to Microsoft but it's not. Exxon Mobil had a good second half of 2017 and weakened with the market January 30. Two days later, it cracked on bad earnings news.

You might say that news did not matter as the entire market got flushed. But look how far the stock fell. It wiped out its entire late 2017 gain. That's not a correction. In fact, we might say the 2017 rally was a correction in a larger bear market.

There you have it. A quick visual inspection of a humble one-year chart with maybe a 50-day moving average is a huge filter when deciding what you must buy if you think this is a healthy correction. I'm not saying any of these stocks here are appropriate but one of them certainly passes through a very important filter. The other two do not.