In the wake of UnitedHealth's  (UNH) - Get Report  results preview and 2020 guidance, the stock is off Tuesday's lows but still down about 1%. 

A few of the metrics were better than expected and some were a little light. No wonder the shares are down a bit as investors digest the news.

Keep in mind, though, that the New York managed-care giant could have preannounced much worse things pertaining to earnings and revenue. While the estimates weren't across the board better than expected, they were more or less in line with expectations.

That's got many investors wondering whether and when UnitedHealth stock is a buy on the dip. It's also got Real Money talking, too, as it has selected UnitedHealth as its Stock of the Day.

Let's take a closer look.

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Trading UnitedHealth Stock

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Above is a daily chart of UnitedHealth stock, while a little further down is a weekly look. Both highlight the significance of the $267.50 area. This mark was notable resistance from second-half 2018 through October 2019.

In November, however, UNH burst over this mark, running to $283. As it starts to unwind a bit, I wouldn't turn outright bearish. Instead, notice how the shares became overbought on the daily chart above (blue circle) and how they ran into 2018 resistance (dashed black line) on the weekly chart below.

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Unwinding some of these gains is a good thing, as it prevents the stock from getting too hot. By giving up some of the gains now, it can give UNH stock the necessary room to run higher.

So when should investors consider buying the dip?

I would love to see a decline down to the $267 to $268 area. Both charts highlight why this would be the ideal pullback zone: It's quite bullish to see a stock finally push through resistance, then decline back down to this level and find that it's now support.

Should shares decline to this level and see it hold as support, look for a rebound back to the highs near $283. Above that mark and the 2018 high of $284.24 is on the table, with new highs above that mark possible.

If $267 to $268 fails as support, that's a bad sign for bulls and could send UnitedHealth stock down to the $255 to $260 area.

For now though, a decline into the $267 to $268 area offers a favorable risk/reward balance for dip buyers. Below it and the narrative will change.

This article is commentary by an independent contributor. At the time of publication, the author had no positions in the stocks mentioned.