Take a look at some of Tuesday's midday movers:
AbbVie - The drug manufacturer and Shire, the Irish company it agreed to purchase in July, both fell a day after the U.S. Treasury Department unveiled plans to curb tax-driven acquisitions. Medtronic and Covidien, the Irish medical supplier Medtronic is trying to acquire, also declined. Mylan and Abbott Laboratories dropped as well, two months after Mylan said it would buy Abbott's generic-drug business. And, Burger King Worldwide declined, less than a month after saying it would purchase Canadian doughnut seller Tim Hortons.
Apple - The iPhone maker climbed after S&P Dow Jones Indices released an analysis that found Apple had repurchased $5 billion of its stock in the second quarter.