Today's noteworthy downgrades include: ACI Worldwide (ACIW) downgraded to Neutral from Buy at Sidoti... Altera (ALTR) downgraded to Market Perform from Outperform at FBR Capital... Cimarex Energy (XEC) downgraded to Hold from Buy at Deutsche Bank... Dillard's (DDS) downgraded to Underperform from Neutral at Credit Suisse... Energizer (ENR) downgraded to Equal Weight from Overweight at Morgan Stanley... Goldman Sachs BDC (GSBD) downgraded to Market Perform from Outperform at Raymond James... Horizon Technology (HRZN) downgraded to Perform from Outperform at Oppenheimer... Nordstrom (JWN) downgraded to Neutral from Outperform at Credit Suisse... Omnicare (OCR) downgraded to Neutral from Buy at Goldman... Steris (STE) downgraded to Sector Weight from Overweight at KeyBanc... Titan Machinery (TITN) downgraded to Neutral from Buy at Sidoti... Twitter (TWTR) downgraded to Hold from Buy at Evercore ISI... Vera Bradley (VRA) downgraded to Neutral at Baird... Verizon (VZ) downgraded to Neutral from Overweight at JPMorgan... WPX Energy (WPX) downgraded to Hold from Buy at Deutsche Bank... Wendy's (WEN) downgraded to Neutral on lack of catalysts at Wedbush... Xilinx (XLNX) downgraded to Market Perform from Outperform at FBR Capital.