Investors in Chipotle Mexican Grill (NYSE:CMG) have been on a wild ride this past year. After the E. coli scare of late 2015, the stock lagged the market's gains by a wide margin throughout 2016, bottoming out at around $353 last winter. Now they're up a whopping 25% since the beginning of 2017, to roughly $470. 

The narrative around the stock has shifted from bearish to bullish, but is the breakout real, or has the stock run too far, too fast? Here are the things investors need to pay attention to in the upcoming earnings release later this month.

Bull and bear figurines.

Image source: Getty Images.

Same-store sales

While revenue, earnings, and earnings per share are important, most investors are probably focused on the all-important same-store-sales figures for the quarter. The first quarter of 2016 marked the low point for Chipotle's same-store sales, when they plunged 29.7% in the wake of the food-safety scandal.

Since Chipotle will be lapping that terrible figure, analysts are predicting roughly a robust 15% same-store-sales increase. While that figure looks great, it would still mean traffic is roughly 19% off from pre-crisis levels.

However, research firm M Science recently wrote that it believes Chipotle will "easily beat" those figures,  after studying traffic patterns for February and early March. Chipotle management also noted on its last conference call in February that the preliminary January comps came in at 24.6%, so we know the company was off to a good start. On the upcoming call, investors should listen for preliminary comps for April, which will paint a clearer picture of current trends.

New marketing campaign

In late March, the company informed investors that after a two-year undertaking, it had finally removed all preservatives from its tortillas, making the Chipotle menu completely preservative-free. The company also called out competitors McDonald's (NYSE: MCD) and Panera Bread (NASDAQ: PNRA) for marketing their menus as "natural," as Chipotle insisted these other restaurants still use preservatives made in a lab.

In the wake of that achievement, Chipotle launched a series of television ads titled "As Real As It Gets." In the ads, the voice of Jeffrey Tambor engages in mock-psychiatry sessions with comedians Jillian Bell, John Mulaney, and Sam Richardson, inside a giant Chipotle burrito, where Tambor encourages them all to "get real." 

It's rare for Chipotle to engage in this type of large-scale video advertising, so investors should listen for the amount of marketing spend planned throughout the year, as well as the long-term target for marketing as a percentage of revenues. And, of course, listen in to see whether the campaign seems to be working so far.

Price increases

In tandem with the new marketing efforts, Chipotle just announced that it's raising prices in about one-fifth of its store base. The price increases are about 5% and only in limited, high-cost markets.

While this may seem like an inopportune time to raise prices, Chipotle hasn't done so since 2014. CFO Jack Hartung noted that since 2012, labor inflation has equaled roughly 20%, while the company has raised prices only 5% in that time. So Chipotle has lagged.  (I can say that Chipotle is almost as cheap as fast food in my area right now.) Investors should keep an ear out for plans for further price increases this year.

Digital Initiatives

Chipotle also just rolled out its new digital ordering system last quarter.  This initiative is supposed to help increase sales, speed up customer wait times for online orders, and help bring in new or lapsed customers.

Investors should listen for how successful this launch has been. Obviously, the primary measure would be the aforementioned same-store-sales figure, but investors should listen for how much of this success or failure is due to the new online ordering and faster pickup system. Other retailers break out digital sales, so investors should see if Chipotle starts doing the same.

What happened to dessert?

Finally, Chipotle previously hinted at new menu items that may come out this year. Last fall, the company rolled out chorizo to all its restaurants and was encouraged by the results. On the third-quarter 2016 conference call, management also said it was experimenting with a dessert and was planning to roll it out "in the near future."  So far it hasn't shown up, and the company neglected to mention the dessert experiment on the last call. Investors should be alert for any new sort of menu innovations that can help drive traffic.

Billy Duberstein owns shares of Chipotle Mexican Grill. The Motley Fool owns shares of and recommends Chipotle Mexican Grill. The Motley Fool owns shares of Panera Bread. The Motley Fool has a disclosure policy.