NEW YORK (AP) -- Stocks that moved substantially or traded heavily Monday on the New York Stock Exchange and the Nasdaq Stock Market:

NYSE

Chesapeake Energy Corp., up 53 cents at $20.80

The natural gas company named Anadarko Petroleum Corp. executive Robert Douglas Lawler as its new chief executive officer.

Red Hat Inc., down $2.34 at $52.65

A BMO Capital Markets analyst downgraded the software company's shares after a big share-price increase in May.

WPX Energy Inc., down $1.30 at $19.76

Hedge fund Taconic Capital Advisors said in a regulatory filing that it now has a 6.39 percent interest in the oil and gas company.

Tellabs Inc., down 14 cents at $2.02

The communications equipment maker said that its chief financial officer is resigning for personal reasons.

Nasdaq

JA Solar Holdings Co. Ltd., up $3.95 at $9.56

The Chinese solar company said that its loss narrowed during its first quarter, helped by stronger-than-expected demand.

Warner Chilcott PLC, up 39 cents at $19.60

Actavis Inc. said that it is buying rival drugmaker Warner Chilcott in an all-stock transaction valued at about $8.5 billion.

Ironwood Pharmaceuticals Inc., down 56 cents at $13.83

A Cantor Fitzgerald analyst reiterated her "Sell" rating on the constipation treatment maker, citing a weak reception to its new drug.

Xenoport Inc., down $1.03 at $5.72

The drug developer said that a potential treatment for multiple sclerosis patients failed in late-stage clinical testing.