Shake Shack IPO Filing Comes Amid A Hunger For Premium Burgers

(Reuters) -- Shake Shack Inc.'s filing this week for an initial public offering underscores a question for investors and foodies alike: How hungry are U.S. consumers for another burger chain? A key part of Shake Shack's growth strategy involves expanding its locations beyond its New York base, and a number of market participants are bullish on its prospects.