Union Pacific has hired the CEO candidate favored by a hedge fund that's been pressuring the railroad to improve. The railroad on Wednesday also cut its outlook after reporting disappointing second-quarter results that it blamed on weakening consumer demand. Union Pacific said its former chief operating officer Jim Vena will take over as CEO next month. Soroban Capital Partners, a hedge fund that that holds a $1.6 billion stake in Union Pacific, had been urging the railroad to hire Vena because of his expertise in streamlining operations. The hedge fund declined to comment on the hiring news but investors endorsed it by sending Union Pacific's stock soaring more than 10%.