Wall Street edged higher in midday trading Thursday, given a slight boost by energy stocks after crude oil topped $60 a barrel. Existing home sales fell 3.3% in April to an adjusted annual rate of 5.04 million. BP (BP) gained after settling with Halliburton (HAL) and Transocean (RIG) over claims related to the 2010 Gulf of Mexico oil spill. BP has now settled all claims with its partners and contractors. CVS (CVS) and Omnicare (OCR) were on the move on Thursday after CVS confirmed it will buy Omnicare for $98 a share in a deal valued at $12.7 billion. The purchase is expected to close by the end of the year.