Shares of Horizon Pharmaceuticals (NASDAQ:HZNP) have traded down 25% since the FDA’s approval of Rayos, the company’s delayed-release arthritis drug, last Thursday. As with most major FDA decisions, investors ran HZNP up 100% in the two months leading up to the July 26th PDUFA – shares peaked at $8.30. Since then, a combination of profit-taking and fears over marketability have scared off many investors. (more…)