By Supantha Mukherjee, Helen Coster and Elizabeth Culliford (Reuters) – U.S. podcaster Joe Rogan apologized and pledged more balance on his show amid a backlash against COVID-19 misinformation on the streaming service that wiped more than $2 billion off its market value last week. On Monday, investors appeared to shrug off the controversy that hurt shares last week, as Spotify’s stock price jumped 12%after brokerage Citigroup raised the stock rating to “buy” from “neutral” saying the Swedish company would be able to improve its advertising business. Spotify said it would add a content advisory…