Top Percentage Gainers and Losers as of 10am 4/21/11 (TRAD, TZOO, SCSS, BIIB, DTLK, ZSTN, HNI, TEVA, OCZ, SINA)

Best

1) TradeStation TRAD: Trading up 30.5% from yesterday's close to $9.67. The company is being acquired by Tokyo-based brokerage Monex Group Inc. for $9.75 per share.

2) Travelzoo TZOO: Trading up 21.8% from yesterday's close to $89.24. The company reported better than expected earnings this morning. Q1 revenue increased 30% year-over-year to $37 million. 3) Select Comfort SCSS: Trading up 21.55% from yesterday's close to $16.20. The company has received numerous upgrades on the heels of an extremely strong Q1 earnings report. Wedbush raised its target price from $11 to $16 per share. Stifel Nicholas raised the target price from $14 to $19 per share. 4) Biogen Idec BIIB: Trading up 20.34% from yesterday's close to $104.05. The company reported strong earnings, posting Q1 EPS of $1.43 versus $1.41 estimates. 5) Datalink DTLK: Trading up 18.94% from yesterday's close to $7.41. Worst 1) ZST Digital Networks ZSTN: Trading down 30.95% from yesterday's close to $3.00. A negative report from Seeking Alpha is crushing the stock this morning. 2) HNI HNI: Trading down 9.8% from yesterday's close to $27.65. The company missed earnings estimates after the bell yesterday. 3) Teva Pharmaceutical Industries TEVA: Trading down 6.6% from yesterday's close to $45.92. Teva's direct competitor, Biogen Idec, reported positive results for its multiple sclerosis drug. The results were far superior to Teva's MS treatment. 4) OCZ Technology OCZ: Trading down 7% from yesterday's close to $7.65. A bearish report from Seeking Alpha, which basically alleges fraud, is taking its toll. 5) Sina SINA: Trading down 5.6% from yesterday's close to $134.85.