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.
Halozyme Therapeutics - The drug developer gained after saying it was closer to reopening a study of pancreatic cancer treatment that was halted by federal regulators last month.
J.C. Penney Company - The retailer jumped ahead of its earnings report on Thursday.
Lululemon Athletica - The maker of yoga clothing rose after research firm ISI Group said the company, as well as Lands' End and Puma, could be takeover targets for apparel maker V.F.
Microsoft - The software maker gained after saying it would cut the cost of its Xbox One gaming console by $100.
Whirlpool - The appliance maker fell after Longbow downgraded it to neutral from buy.
W.W. Grainger - The distributor of maintenance and repair supplies declined after reporting April sales rose by 5 percent.
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—By CNBC's Rich Fisherman.
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