Adobe (ADBE) CEO Shantanu Narayen is stepping down after 18 years in the role, the company announced on Thursday in conjunction with its first quarter earnings report. Adobe stock fell more than 8% during premarket hours on Friday following the news. Narayen will leave the post when a successor is found, but he will remain as chair of the board afterward. The company's board also appointed Frank Calderoni, lead independent director of Adobe, as chair of the special committee that will look for CEO candi ...