Halliburton Co., up $2.08 at $39.29
The oilfield services company says it lost $18 million in the first quarter, but its results still beat Wall Street expectations.
Six Flags Entertainment Corp., up $5.86 at $77.11
The amusement park operator took a smaller loss in the first quarter as its attendance rose 41 percent compared with last year.
AbbVie Inc., up $1.81 at $44.20
A Morgan Stanley analyst upgraded the drugmaker's stock, saying he expects greater sales of its anti-inflammatory drug Humira.
Met-Pro Corp., up $3.78 at $13.38
CECO Environmental Corp., which makes ventilation systems, said it is buying the maker of water-treatment equipment for $202.1 million.
Hasbro Inc., up $1.53 at $46.55
The maker of Transformers, My Little Pony and G.I. Joe toys reported first-quarter results that beat Wall Street expectations.
Celgene Corp., up $4.48 at $126.84
A Cantor Fitzgerald analyst raised her price target on the drugmaker's stock, citing its new products and experimental drugs.
AmTrust Financial Services Inc., down $1.40 at $31.29
The insurer said that it completed its acquisition of Sequoia Insurance, the provider of casualty insurance, for about $60 million.
Power-One Inc., up $2.29 at $6.33
ABB Ltd., the Swiss power technology company, said that it is buying the solar equipment maker for about $1 billion.