Take a look at some of Monday's midday movers:
Allergan - The Botox maker declined after saying the U.S. Food and Drug Administration had delayed a decision about its application for an acute migraine aerosol.
The Bank of New York Mellon - The bank jumped on news activist investor Nelson Peltz's Trian Fund had purchased about a 2.5 percent stake in the company.
Dicerna Pharmaceuticals - Shares of the drug developer soared after it reported positive results from preclinical data on its experimental liver disease drug.
GW Pharmaceuticals - The company gained ground after Piper Jaffray raised its price target to $147 from $97 a share.
Illunina - The life-science tools developer rose after Wedbush said the company may have won an exclusive competitive contract with Progenity.
International Paper - The producer of corrugated shipping boxes jumped after Barron's said its shares may increase 40 percent in the next 12 months.
Lennar - The home building and competitors including KB Home, PulteGroup, DR Horton and Toll Brothers advanced on news pending-home sales hit an eight-month high in May.
Linn Energy - The oil and natural-gas company rose after it acquired U.S. non-core oil and gas assets of Devon Energy for $2.3 billion.
MBIA - The bond insurer fell after BTIG downgraded the stock to neutral.
Merck & Co. - The pharmaceutical company rose after reporting positive trial results for its nausea drug for children.
Norfolk Southern - The railway advanced after being upgraded to overweight from equal weight at Barclays.
Oasis Petroleum - The energy exploration company climbed after Raymond James upgraded the stock to a strong buy from outperform.
PPG Industries - The paint and coating makers rose saying said it would acquire Consorcio Comex SA de CV, a Mexican maker of coatings and related products, for $2.3 billion.
Treehouse Foods - The food producer gained on news it's buying Flagstone Foods for $860 million from private-equity firm Gryphon Investors.
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—By CNBC's Rich Fisherman.Questions? Comments? Email us at marketinsider@cnbc.com