Pandora (P -2.9%) has slumped to new post-IPO lows today. Boutique equity trading firm National Alliance has launched coverage with a Market Perform, arguing strong ad sales growth is offset by licensing costs and emerging competition from the likes of Apple and Spotify. Separately, 125 musicians have signed a letter opposing Pandora's efforts to bring Internet radio royalties in-line with satellite royalties, via the Internet Radio Fairness Act.