Starbucks (NASDAQ: SBUX) stock needed a double shot of espresso Friday, as shares slumped following disappointing December quarter results and guidance. With shares down 5 percent, investors may have reached for a double shot of something slightly stronger.

Concerns centered on decelerating sales, with comps increasing just 2 percent compared to the consensus of 3 percent. The low comp stoked worries about 2018 performance, though Starbucks said its still sees 3 to 5 percent comparable store sales growth globally, but near the low end of the range.

“...limited-time holiday beverages, holiday gift-cards and holiday merchandise available for purchase in our stores' lobby underperformed in Q1,” said Starbucks CEO Kevin Johnson.

Weakness was not, Johnson said, related to it losing share or it cannibalizing itself.

Comps came in below guidance because early strength “petered out,” said Sara Senatore, an equity analyst at Bernstein.

“While F1Q started with healthy momentum, soft lobby sales (merch/gift cards) drove back half [deceleration] and a slower start to F2Q. Although lobby sales growth has been negative for several years, the stakes are higher with the core comp slowing to ~3%,” said Senatore. “One bright spot was reacceleration of [My Starbucks Rewards] members, but it was not enough to offset declines in more casual Starbucks users.”

Senatore has an Outperform rating on the stock.

Deutsche Bank analyst Brett Levy also commented on Starbucks' December quarter, stating, “SBUX remains an unquestionably strong brand with solid economics and among the most revered technologies, but the recent sales trends and profit outlooks have created an environment where Bulls and Bears have found alternating times to take stands. We rate SBUX shares a Buy as the recent resets, unit-level, product, marketing, technology and global initiatives all represent opportunities for the business to re-accelerate, but we have become a little more cautious on the slower SSS trends.”

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