Keryx downgraded By: MarketMinute.com Stock News September 08, 2014 at 12:28 PM EDT FBR Capital downgraded Keryx Biopharmaceuticals Inc. (Nasdaq: KERX) from a Market Perform rating to an Underperform rating sending the stock price tumbling $1.55 to $15.46. Related Stocks: Keryx Biopharm Inc