It was a busy 2018 for Constellation Brands (STZ -0.23%), with the alcoholic beverage giant riding strong demand for its premium imported beers to deliver market share gains and another increase in profitability. The owner of the Corona and Pacifico franchises also made an aggressive bet in the marijuana space that started small but grew into a massive $4 billion investment in Canopy Growth (CGC -2.79%).

Investors have lately found more reasons to be cautious about Constellation Brands' business, though, as rising marketing costs appear set to push profit growth below 20% for the first time in five years. Those contrasting trends set shareholders up for an important earnings announcement on Jan. 9, one that could set the stage for a better year ahead for this high-flying stock.

With that backdrop in mind, let's take a closer look at the major metrics that will shape Constellation Brands' fiscal third quarter.

Market share

Beer sales have been the main engine powering Constellation Brands' business growth since 2013, when the company acquired the U.S. selling rights to imported brands like Corona. That trend has held up in 2018, too, with consumption rising by 10% over the past six months while giants like Anheuser-Busch InBev have reported flat or slightly declining results in the U.S.

This upcoming report will include an important update on that market share fight. It will also show whether Corona Premier, the first national addition to the franchise in 25 years, is still meeting management's expectations. Executives have been saying since the start that beer sales should grow by about 10% this fiscal year, and any shift to that target would reflect slower or faster-than-expected growth over the last few months.

Profitability and spending

CEO Rob Sands and his team are predicting that profitability will rise again in fiscal 2019 to continue an impressive streak that's seen operating margin jump to 30% from 22% five years ago. This rally has been helped along by robust demand and rising selling prices. That's just one of the benefits of Constellation Brands' premium positioning.

Profit gains are slowing, though, for a few reasons. The main one is accelerated marketing spending in support of key brands and the launch of Corona Premier. Constellation is also allocating lots of cash toward expanding and upgrading its Mexican brewery network. Management has sought to assure investors that these spending programs will be temporary and will generate high returns, but Wall Street will be looking for the company to back up those words by forecasting a slowdown in expense growth perhaps as soon as 2019.

Marijuana updates

Executives warned back in early October that their equity investment in Canopy Growth, which closed a few weeks later, might produce earnings volatility due to potential charges tied to shifts in the value of the marijuana specialist's stock. Shareholders will get a quick look at that risk since Canopy Growth's shares are down about 40% over the last three months.

Marijuana in a jar.

Image source: Getty Images.

Any accounting charge that Constellation Brands takes isn't likely to affect its outlook for the business, though, and it might in fact produce a more attractive purchase price for company to boost its stake. Their partnership gives Constellation a 35% ownership level that management can increase to above 50% if the markets in Canada and in the U.S. develop as quickly as they're hoping they will.

Check out the latest Constellation Brands earnings call transcript.