Shares of Starbucks Corp. (SBUX) must be drinking extra strong coffee in 2019. 

It's been a roller-coaster environment for the broad market, with the S&P 500 down double-digits since the calendar flipped to October. After posting the worst December returns in decades, the S&P is kicking off 2019 in rebound mode, charging higher in the fastest recovery since 2009.

The about-face is tiring out investors who are stuck wondering whether we've seen the last of the selling, at this point.

The most important question for surviving the back-and-forth is still a simple one: "What's working in this environment?"

One very clear answer is Starbucks.

Shares of Starbucks are up more than 30% since the calendar flipped to second-quarter 2018, outperforming in a meaningful way during a stretch when outperformance was hard to come by. More importantly, the uptrend in this coffee chain is alive and well as markets head deeper into January.

To figure out how to trade it, we're turning to the charts for a technical look:

At a glance, it doesn't take a trading whiz to figure out that Starbucks has been in an uptrend since the final days of June 2018. Shares managed to hold onto an incredibly well-defined, low-volatility uptrend in the months that followed, and the stock surged in November, while the broad market floundered.

After cooling off in December, Starbucks reaffirmed its ability to catch a bid at trendline support late in the month, and shares have been pointing up and to the right ever since.

Simply put, Starbucks is still a "buy the dips stock" this winter, thanks to that successful support test a couple of weeks ago. And with shares bouncing off of support again in January, now looks like a buyable dip.

Importantly, support has been a much stronger technical level than the return line that bounded Starbucks' upside moves during the third and fourth quarters of last year. That means shares could see a return to materially higher levels under a best-case scenario for the markets. Otherwise, a low-volatility uptrend looks likely to remain intact.

Relative strength has been holding onto higher lows in Starbucks, indicating that the systematic outperformance this stock has exhibited over the last couple of quarters continues to work in 2019. For Starbucks bulls, the $60 level looks like a logical place to park a protective stop; if $60 gets violated, then the uptrend that's corralled shares higher is officially over. Meanwhile, Starbucks looks like a good way to get exposure to low-volatility positive momentum in this roller-coaster market.

The stock closed up Thursday 0.49% at $64.19.

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