The companies whose shares are moving in early session on Tuesday are: Boyd Gaming, Synchronoss Technologies, Select Medical Holdings, athenahealth, Centene, Avon Products, Steris Corp., Halliburton and Blackbaud.

Gainers

Boyd Gaming Corp. (NYSE:BYD) shares gained 12.81 percent to $12.43 in early trading as the company stock was upgraded to “buy” from “underperform” with a price target of $16.

Synchronoss Technologies, Inc. (NASDAQ:SNCR) shares surged 10.69 percent to $34.38 in early trading as J.P. Morgan Chase & Co. raised its price target on shares of SNCR to $33.50 from $28after the company reported better than expected earnings

Select Medical Holdings Corp. (NYSE:SEM) shares climbed 7.35 percent to $7.30 in early trading. The stock has a 52 week low of $5.62 and 52 week high of $9.19 and has $1.18 billion market capitalization.

athenahealth, Inc. (NASDAQ:ATHN) shares advanced 7.26 percent to $49.45 in early trading . The company stock was upgraded to “Outperform” rating from “market perform” at Wells Fargo.

Centene Corp. (NYSE:CNC) shares gained 7.17 percent to $29.74 in early trading hours. The company posted fourth quarter net earnings attributable to Co. of $25.39 million from $23.71 million in the same period a year-ago.

Sandisk Corp. (NASDAQ:SNDK) shares advanced 3.24 percent to $49.35 in early session. The company stock was upgraded to “buy” rating from “neutral” rating at Sterne Agee.

Losers

Steris Corp. (NYSE:STE) shares declined 7.19 percent to $33.23 in early trading session as the company lowered its fiscal 2011 guidance for revenue growth and expects revenue to increase 2 percent compared with fiscal 2010 levels against its previous estimation of 5 percent growth.

Avon Products Inc. (NYSE:AVP) shares declined 6.76 percent to $27.34 in early trading hours. Its fourth quarter net income fell to $220 million or $0.50 per share, down from $268 million or $0.62 per share in the same period a year-ago.

Halliburton Co. (NYSE:HAL) shares declined 3.77 percent to $44.45 in early trading session. The stock has a 52 week low of $21.10 and 52 week high of $47.22 and has $40.39 billion market capitalization.

Blackbaud, Inc. (NASDAQ:BLKB) shares declined 6.29 percent to $24.97 in early trading session. The company reported fourth quarter net income of $8.5 million or $0.20 per share compared to $8.0 million or $0.18 per share for the same period a year-ago.

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