Top Percentage Gainers and Losers as of 10 am 4/18/11 (AMRN, INVE, THOR, TITN, AONE, HTWR, GKK, CYH, VPHM, KONG)

Best

1) Amarin Corporation (NASDAQ: AMRN): Trading up 79% from Friday's close to $15.70. A positive phase III trial of the company's main product has shares vaulting this morning. The drug, AMR101, significantly lowered triglycerides without causing a rise in “bad” cholesterol.

2) Identive Group (NASDAQ: INVE): Trading up 15.5% from Friday's close to $3.88.

3) Titan Machinery (NASDAQ: TITN): Trading up 14.8% from Friday's close to $30.91. Company reported better than expected earnings.

4) Thoratec (NASDAQ: THOR): Trading up 14.2% from Friday's close to $31.34. Company was upgraded from Neutral to Buy at Lazard.

5) A123 Systems (NASDAQ: AONE): Trading up 8.7% from Friday's close to $5.99.

Worst

1) Gramercy Capital (NYSE: GKK): Trading down 17.6% from Friday's close to $3.35. A two-week extension of the maturity dates of a $240.5 million mortgage loan and a $549.7 million junior and senior mezzanine loans has shares falling.

2) Heartware International (NASDAQ: HTWR): Trading down 13.57% from Friday's close to $72.52. Positive results for rival Thoratec's (NASDAQ: THOR) heart device has shares plunging.

3) Community Health Systems (NYSE: CYH): Trading down 10% from Friday's close to $28.74.

4) VioPharma (NASDAQ: VPHM): Trading down 9.5% from Friday's close to $19.73.

5) KongZhong (NASDAQ: KONG): Trading down 8.2% from Friday's close to $9.90.