Shares of Baidu (NASDAQ: BIDU) tumbled 10% on May 18, after the company announced the upcoming departure of COO Qi Lu in July. Prior to joining Baidu in early 2017, Lu served as Microsoft's executive VP of its Applications and Services Group. As one of the industry's leading AI experts, Lu played a key role in Baidu's transition from an online search company to a cloud and AI services provider.When Lu initially joined Baidu, CEO Robin Li stated: "With Dr.