Starbucks Corporation (SBUX) has been on a roll lately, with the stock appreciating 21.7% in the past month compared with the Zacks Retail – Restaurants industry’s 7.9% rise. But what’s fueling this caffeine-fueled rally and is it a good time for investors to jump in?The recent upside was sparked by the company’s announcement that Brian Niccol will replace Laxman Narasimhan as CEO on Sep. 9. Starbucks has faced challenges under Narasimhan, including declining same-store sales in the United States, staffing ...