Friday's Early Winners & Losers

Gmarket (GMKT) shares plummeted by more than 17% in extended trading Thursday as the South Korea-based online retailer posted lower-than-expected earnings. Its per-share bottom line was up by 4 cents a share from last year to 13 cents, or $6.8 million, but analysts polled by Thomson Financial were seeking 15 cents. Revenue, at $51.6 million, was $7.7 million short of consensus estimates, despite surging 67% from a year ago. Shares were losing $3.40 to $16.49.

Quiksilver (ZQK), a maker of winter-sports apparel and equipment, suffered under the unseasonably warm fiscal first-quarter weather. The company saw earnings plunge year over year to $2.5 million, or 2 cents a share -- 2 cents below Wall Street expectations. Year-ago profits had been $18.6 million, or 15 cents a share. Chief Executive Robert McKnight called this winter-sports season "the worst in decades." Shares were off $1.57, or 12.1%, to $11.39.

Lumera (LMRA) widened its fourth-quarter losses by a penny a share to 17 cents, or $3.1 million, from a year ago. The Bothell, Wash., company, which makes polymer-based devices for the bioscience and electro-optics industries, was tumbling 36 cents, or 7.9%, to $4.19.

Tercica (TRCA), which had risen sharply Wednesday on a favorable patent-infringement suit settlement, lost ground in Thursday's after-hours trading after burgeoning expenses helped to double its per-share losses to 85 cents, or $41 million, in the fourth quarter. The Brisbane, Calif., biotech said R&D costs totaled $29.3 million, up sharply from $4.7 million last year because of a $25 million licensing fee. Shares were falling 31 cents, or 5.8%, to $5.