What happened

Shares of Zoe's Kitchen Inc. (NYSE:ZOES) were up 9.2% as of 3:30 p.m. EDT Thursday after an analyst upgraded shares of the Mediterranean-themed fast-casual restaurant chain ahead of its second-quarter 2017 report.

More specifically -- and keeping in mind that Zoe's is poised to release formal quarterly results after the market close today -- Telsey Advisor Group upgraded Zoe's stock from market perform to outperform. Today's jump also follows a similar positive move yesterday, which came despite no company-specific news.

A table with Mediterranean food from Zoe's Kitchen

IMAGE SOURCE: ZOE'S KITCHEN

So what

Zoe's stock is still down more than 40% so far in 2017 as of this writing, given today's difficult restaurant-industry environment. This has resulted in a pair of painful quarterly reports earlier this year that included the company breaking a 28-quarter streak of positive comps. At the same time, Zoe's has implemented a number of initiatives to return to comparable-sales growth, including "back-of-the-house simplification" efforts to improve guest experience and throughput, a new menu rollout in in late June, and a new website earlier this month featuring improved online ordering capabilities.

Now what

For perspective, Zoe's latest guidance (provided in May) called for full-year 2017 revenue to be between $314 million and $322 million, and for 2017 comparable-restaurant sales to be in the range of negative 3% to flat from 2016. Zoe's also told investors to expect restaurant contribution margin for the year of between 18.3% and 19%.

Whether Zoe's reiterates or changes that guidance remains to be seen. But either way, tonight's release will provide much-needed color on whether its efforts are yielding fruit.

Steve Symington has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Zoe's Kitchen. The Motley Fool has a disclosure policy.