Afternoon Market Losers

Amicus Therapeutics FOLD plunged 24.45 percent to $2.41. Amicus Therapeutics shares have dropped 38.30% over the past 52 weeks, while the S&P 500 index has gained 21.14% in the same period.

Terex TEX dropped 9.59 percent to $28.70 after the company lowered its FY13 earnings guidance.

Medivation MDVN tumbled 9.52 percent to $46.02 after a morning of high-volume trading.

Celsion CLSN dropped 9.23 percent to $1.18 with a 12 month ROE of -79.88 percent.

Alpha Natural Resources ANR traded down 7.67 percent to $5.54 after Raymond James downgraded the stock to Underperform.

Nevsun Resources NSU decreased 5.92 percent to $3.26 on precious metals sector lagging in the market.

Pixelworks PXLW fell 8.32 percent to $3.76 after reaching its 52 week high of $4.11 last week.

EDAP TMS EDAP dropped 12.70 percent to $2.75.