After-Hours Movers Monday: Black Diamond Inc., LeapFrog Enterprises Inc

Arotech Corp. ARTX jumped more than 9 percent after hours Monday, to $3.15. The Ann Arbor, Michigan defense and security products and services company said fourth-quarter revenue grew 36 percent. Black Diamond Inc. BDE climbed 7 percent in late trading Monday. The Salt Lake City, Utah, maker of mountaineering gear and athletic apparel posted adjusted earnings growth of 36 percent for its fourth quarter. Jumei International Holding Ltd. JMEI gained about 6 percent n Monday's extended session, changing hands recently at $14. The Beijing online retailer of beauty products posted a fourth-quarter profit after the bell, compared with a year-earlier loss. Amarin Corp. plc AMRN rose about 5 percent to $3 in late trading. The Dublin-based biopharmaceutical company's shares have gained more than 50 percent since last week when it signed a licensing agreement in China for its Vascepa treatment for lowering blood levels of triglyceride related to heart disease. LeapFrog Enterprises Inc. LF jumped more than 3 percent in the extended session to $2.16, after closing down 9 percent earlier Monday. Shares of the Emeryville, California maker of educational toys are down more than 50 percent since posting disappointing quarterly results in February. Dynamic Materials Corp. BOOM blasted down 12 percent to $12.71 on a disappointing fourth-quarter earnings report. The industrial infrastructure and oilfield services company said lower energy prices will hurt results going forward. Enzo Biochem, Inc. ENZ declined 11 percent in late trading to $2.71, extending earlier losses on an unfavorable court ruling on its DNA sequencing patent versus Thermo Fisher Scientific Inc.'s TMO Applera unit. Knoll Inc. KNL fell nearly 7 percent in Monday's after-hours session to $20.96, after closing up by the same percentage. The East Greenville, Pennsylvania company didn't issue any news. 58.com Inc. WUBA fell about 3.5 percent in late trading to $44.20. The China-based online market place provider's shares are up nearly 10 percent since posting fourth-quarter earnings last week.