Starbucks' stock is on the rise again. Check out how a CEO change drove a quick 21% price gain.Shares of Starbucks (SBUX -0.91%) soared 21.3% higher in August 2024, according to data from S&P Global Market Intelligence. The giant coffee chain only had a single piece of game-changing news last month, but it was a big one. After 17 months on the job, CEO Laxman Narasimhan was pushed out to make room for a food service superstar. Starting on Sept. 9, former Chipotle Mexican Grill (CMG -0.34%) CEO Brian Niccol ...