Take a look at some of Tuesday's midday movers:
Allergan - The drugmaker rose after Valeant Pharmaceuticals International said it would "improve" its unsolicited $47 billion bid for the company.
Dow Jones Transportation Average - The index advanced to a record, with Delta Air Lines, Alaska Air Group, Union Pacific, Ryder System, and Con-way all posted strong year-to-date gains.
ExamWorks Group - The provider of medial exams and bill reviews fell after offering 3.1 million shares of stock at $33.90.