Are Americans starting to tire of their Shake Shack fix? While the chain may have nurtured a cult following among some New York City burger aficionados, its tumbling share price may reveal some important changes in Americans’ eating habits and some key risks that may spell trouble for its future valuation.

While a Thomson Reuters consensus estimate foresaw $63 million in revenue, the company beat expectations with sales of $66.5 million. Despite these results, shares plunged 15 percent since its earnings announcement on August 10, and its share value has dropped 35 percent over the past year.

Same-store sales have slowed considerably, growing just 4.5 percent compared to 17.1 percent in 2015, which could be the result of deflationary food prices keeping customers at home rather than in restaurants.

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“There’s no doubt there’s been a lot of choppiness out there, throughout so much of our industry, in all phases of our industry, all the way from casual to fast food,” said CEO Randy Garutti, during the company’s second-quarter earnings call. Garutti acknowledged that minimum wage increases are creating wage pressures that will continue to impact on their overhead costs year-over-year.

Shake Shack is not alone among restaurants increasingly squeezed by higher labor costs and lower food prices that allow minimum flexibility to compete with restaurants. The gap between restaurant and grocery store prices can be seen in the Bureau of Labor Statistics CPI data on food away from home (including restaurants) compared to food at home (grocery stores).

Analysts note that with food prices falling, Shake Shack’s premium priced burgers may seem even more expensive compared to eating at home.

“We also point out another detriment specific to restaurants of 250 bps of higher food away from home CPI so far in 2016 relative to food at home, the widest gap since 2009,” wrote Cowen and Company analyst Andrew Charles in a research note. 

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