Shares of Shake Shack Inc. (SHAK) have rallied 26.7% in the past three months, significantly outperforming the 7.8% growth registered by the Zacks Retail - Restaurants industry. SHAK also outpaced the broader Retail-Wholesale sector and the S&P 500 index's 14.8% and 7.8% growth, respectively, during the same period.The company is benefiting from strong same-shack sales, digital initiatives and unit expansion efforts. Also, focus on strategic promotions and effective marketing campaigns, along with menu inno ...