Afternoon Market Losers

Orchard Supply Hardware Stores OSH plummeted 64.16 percent to $1.11 after the company filed its Chapter 11 bankruptcy, putting equity holders' entire investment on the line.

Vanda Pharmaceuticals VNDA dropped 23.53 percent to $8.35. Vanda's PEG ratio is -0.83.

Tetra Tech TTEK tumbled 12.87 percent to $3.44 after the company projected to post a loss in the third quarter.

Vitesse Semiconductor VTSS plunged 11.82 percent to $2.42 after the company announced a public offering of $30 million common shares.

Vipshop Holdings Limited VIPS dipped 9.79 percent to $29.76 on no particular news.

Biodel BIOD fell 9.67 percent to $4.30 after the company announced the pricing of an underwritten public offering of 4,482,760 shares of its common stock at a public offering price of $4.35 per share.