Top Percentage Gainers and Losers as of 12pm 09/07/11

Best

1) MELA Sciences (NASDAQ: MELA): Shares of MELA are currently trading up 58.4% from yesterday's close to $3.54. The company's diagnostic device, MelaFind, used to detect skin cancer won European Union approval. The stock has broken above its 200-day simple moving average (one year daily chart) in today's session.

2) Conn's (NASDAQ: CONN): Shares of Conn's are currently trading up 29.6% from yesterday's close to $7.05. The company reported Q2 earning s of $0.17 per share versus estimates of $0.11 per share. Sales came in at $184.4 million versus the forecast of $184.83 million. As far as guidance, Conn's is earnings between $0.64 and $0.75 per share, above estimates of $0.54 per share.

3) Walter Energy (NYSE: WLT): Shares of Walter Energy are currently trading up 28% from yesterday's close to $95.85. There are rumors that Anglo American PLC is preparing a bid for Walter of $120 per share, and has lined up financing which will support a bid of up to $150 per share. The stock has seen a huge jump in options activity in today's session.

4) MGIC Investment (NYSE: MTG): Shares of MGIC are currently trading up 23.6% from yesterday's close to $2.83. The company reported that it has written $1.3 billion worth of new insurance in August. MGIC also reported that it has seen a drop in delinquent loans – from 185,093 to 183,338. The stock recently hit a 52-week low of $1.59 on August 23rd.

5) Petroleum Development (NASDAQ: PETD): Shares of Petroleum Development are currently trading up 22.2% from yesterday's close to $26.57. The company announced plans to acquire land in southeastern Ohio, targeting wet gas and oil phases of Utica Shale. The stock hit a 52-week low of $20.86 in yesterday's session.

Other Notable Gainers

SuperMedia (NASDAQ: SPMD): Shares of SuperMedia are currently trading up 20.2% from yesterday's close to $2.64.

Deer Consumer Products (NASDAQ: DEER): Shares of Deer are currently trading up 16.1% from yesterday's close to $4.68.

Westport Innovations (NASDAQ: WPRT): Shares of Westport are currently trading up 15.3% from yesterday's close to $26.31.

Worst

1) VASCO Data Security International (NASDAQ: VDSI): Shares of VASCO are currently trading down 10.6% from yesterday's close to $5.98. The company was downgraded from Buy to Hold at Wunderlich Securities. The price target was moved from $15.50 to $7.

2) Mecox Lane (NASDAQ: MCOX): Shares of Mecox are currently trading down 9.5% from yesterday's close to $2.13. The company reported a Q2 loss of $3.4 million versus net income of $4.1 million for the same period last year. Gross profit declined 20.1% year over year – from $26.9 million to $21.5 million.

3) VanceInfo Technologies (NYSE: VIT): Shares of VanceInfo are currently trading down 4.7% from yesterday's close to $11.45. The stock started off the session in positive territory, but has been sold of since the opening bell.

4) KongZhong (NASDAQ: KONG): Shares of KongZhong are currently trading down 4.6% from yesterday's close to $4.11. The company reported a 70% jump in Q2 earnings, more than doubling revenue and reducing development costs.

5) DRDGOLD (NASDAQ: DROOY): Shares of DRDGOLD are currently trading down 4.6% from yesterday's close to $5.36.

Other Notable Losers

Liquidity Services (NASDAQ: LQDT): Shares of Liquidity Services are currently trading down 4.2% from yesterday's close to $30.39.

Zion Oil & GAS (NASDAQ: ZN): Shares of Zion are currently trading down 3.8% from yesterday's close to $2.31.