Investors haven't been sure what to make of McDonald's (NYSE:MCD) in 2019, and that confusion shows up in returns that have swung between modest losses and slight gains for the stock compared with the S&P 500. On the bright side, the fast-food titan is enjoying accelerating global growth and rising profitability. But competition in the core U.S. market is creating a knock-down, drag-out fight for share, especially as consumers shift demand toward home delivery.

With that bigger picture in mind, let's look at the trends that investors will be watching when Mickey D's posts third-quarter results on Tuesday, Oct. 22.

Friends sharing a fast-food meal.

Image source: Getty Images.

Traffic trends

The chain's global growth picture is decidedly positive, with worldwide comparable-store sales landing 6.5% higher last quarter compared with 5.4% in the previous quarter. That success includes almost 6% growth in the international business and a 5.7% spike in the core U.S. division.

The U.S. sales pace was particularly good news because it suggested market share gains against challengers like Shake Shack, which expanded comps by just 3.6% in the most recent quarter. Yet the better-burger upstart has something that McDonald's has been missing lately: rising customer traffic. Transaction volume has been sinking for over a year at McDonald's, and executives said back in July that returning to growth on that metric is a top priority. Investors will be looking for signs of progress on that score over the last few months.

What's working

Delivery offerings are supporting sales volumes and pushing average spending higher in the industry. And that helps explain why just about every restaurant stock -- from fast-food to full-service dining and across niches like pizza, burgers, and Tex-Mex -- is attacking the e-commerce channel. McDonald's has put tons of resources behind this initiative as part of the $1.6 billion investment that marks its biggest annual real estate spending project to date.

Beyond updates on how that remodeling plan is lifting sales, CEO Steve Easterbrook and his team should highlight a few other initiatives that they see as core weapons in their street fight for market share. These include limited-time launches like the latest McRib release, along with aggressive promotions in its value menu.

Spending plans

McDonald's faster growth profile has come at a hefty price. While it is expanding sales at a rate that investors haven't seen since all-day breakfast hit the menu in late 2015, it has had to make dozens of major changes in areas like its menu, sourcing, supply chain, marketing, and ingredients list. At the same time, it is pouring billions into remodeling and upgrading restaurants at a pace of about 1,000 per month. "Getting to these results wasn't easy," Easterbrook told investors in late July.

The stock's long-term returns from here will depend on management's ability to keep innovating and changing at this elevated pace. If the competition has any say, then there might be significant financial costs for maintaining that posture.

McDonald's second-quarter report didn't show signs of a competitive surge hurting its global expansion. But the chain might project slower growth in 2020 and beyond, just as rival Domino's announced to its shareholders in early October.