After a challenging last year, 2019 has been a stellar start for stock market investors. The about-face has been a welcome one, but not all stocks are surging in the new year.

Take AT&T (T - Get Report) , for instance. Shares of the communications giant have basically stayed flat all year, up just 2.6% since the calendar flipped to January. During a typical year, that wouldn't be a bad number just seven weeks into things.

But in 2019, with the big S&P 500 index already flirting with 10% total returns on the year, it's a pretty noticeable bit of underperformance. That's the bad news.

The good news is that AT&T's laggard status could finally be about to change.

The stock closed up 0.10% at $29.84 Wednesday.

To figure out how to trade it from here, we're turning to the chart for a technical look.

At a glance, the sideways grind in AT&T has been hard to miss. But that sideways slug is also what's driving the bullish rebound-pattern in shares this winter.

Since late October, shares of AT&T have been forming an inverse head-and-shoulders pattern, a bullish reversal setup with a silly name but meaningful trading implications.

The price pattern in AT&T indicates exhaustion among sellers. It's formed by a pair of swing lows with a deeper swing low in between them - and the buy signal comes on a breakout through AT&T's neckline, currently at the $31 level. A break through $31 clears the way to a retest of multi-month highs set before the correction kicked off last fall.

Don't let the silly name fool you; the head and shoulders is an effective trading setup. An academic study conducted by the Federal Reserve Board of New York found that the results of 10,000 computer-simulated head-and-shoulders trades resulted in "profits [that] would have been both statistically and economically significant."

AT&T's momentum gauge - 14-day RSI up at the top of the chart - has been making higher lows of its own as its stock price carved out the reversal setup. That adds extra confidence to the notion that buyers are taking back control of AT&T right now.

It's also worth noting that long-term trendline resistance that's harangued shares of AT&T for most of 2018 is currently on a collision course with this stock's $31 neckline. Simply put, if the breakout brings AT&T's stock price above its neckline and trendline resistance at the same time, it adds a higher-probability that what we're seeing is a long-term trend reversal, not just a flash in the pan.

Patience continues to be a virtue in shares of AT&T. Wait for the $31 breakout to happen before you pull the trigger on this trade.

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