Tuesday's Early Winners & Losers

AngioDynamics (ANGO Quote) gained after the Queensbury, N.Y.-based medical-device company beat Wall Street's first-quarter earnings expectations. The company reaffirmed its fiscal 2007 guidance of about $9.8 million in earnings, or 60 cents a share, and sales of roughly $101 million. Shares were climbing $1.35, or 7%, to $20.60.

Siga Technologies (SIGA Quote) soared more than 80% after its merger partner PharmAthene received a contract valued at up to $213 million from the Defense Department Army Space and Missile Command. The contract covers the advanced development of the company's chemical nerve agent prophylaxis, Protexia. Shares of Siga climbed 85 cents to $1.91.

Merix (MERX Quote) sank after the Forest Grove, Ore.-based printed circuit board maker lowered its first-quarter earnings guidance. Shares were falling $2.94, or 21%, to $11.11.

Arena Pharmaceuticals (ARNA Quote) fell after saying an investigational niacin receptor agonist that was being developed under its partnership with Merck (MRK Quote) to develop drugs for the treatment of atherosclerosis and other disorders is no longer in development for the treatment of atherosclerosis. Arena was losing 75 cents, or 6.1%, to $11.50.

PMC-Sierra (PMCS Quote) tumbled after the Santa Clara, Calif.-based semiconductor company lowered its projected revenue for the third quarter, citing sluggish sales of its communications products. Shares were trading down 48 cents, or 7.3%, to $6.07.

Lowe's (LOW Quote) slipped after the seller of home-improvement products said full-year earnings would be near the low end of its earlier guidance. The company cited weaker-than-expected sales and a cautious consumer outlook. Shares of Lowe's were down 4 cents to $28.80.