Power One Inc, Delhaize Group, Zynga, Silver Wheaton, Yahoo, Koninklijke Philips, Omthera Pharmaceuticals, Vertex Pharmaceuticals and ArcelorMittal are among the companies whose shares are moving in the pre-market trading Monday.

Gainers

Power One Inc. (NASDAQ:PWER) stock rallied 53.71 percent to $6.21 in pre-market trading. The company announced on Monday that their boards of directors have agreed to a transaction in which ABB will acquire Power-One for $6.35 per share or about $1 billion equity value, which includes Power-One's net cash of $266 million.

Delhaize Group (NYSE:DEG) stock climbed 11.14 percent to $61.85 in pre-market trading after the company announced preliminary first quarter results. Underlying operating profit surged 13.7 percent to 214 million euros compared to same quarter, last year. Quarterly revenues were 5.5 billion euros, an increase of 2.1 percent and 1.5 percent at identical and actual exchange rates, respectively.

Zynga Inc. (NASDAQ:ZNGA) stock surged 3.45 percent to $3.30 in pre-market trading. The stock has a 52-week low of $2.09, a 52-week high of $9.81 and $2.51 billion in market capitalization.

Silver Wheaton Corp. (NYSE:SLW) stock gained 2.64 percent to $23.33 in pre-market trading. The stock has a 52-week low of $21.79, a 52-week high of $41.30 and $8.06 billion in market capitalization.

Yahoo! Inc. (NASDAQ:YHOO) stock advanced 1.32 percent to $23.78 in pre-market trading. The stock has a 52-week low of $14.59, a 52-week high of $24.99 and $26.17 billion in market capitalization.

Losers

Koninklijke Philips Electronics N.V. (NYSE:PHG) stock plunged 3.67 percent to $27.26 in pre-market trading. Its first quarter net profit declined to 162 million euros from 183 million euros in the same period last year. Quarterly sales declined 1 percent to 5.26 billion euros compared to 5.037 billion euros last year due to negative impact of currency effect and portfolio changes.

Omthera Pharmaceuticals Inc. (NASDAQ:OMTH) stock plunged 2.59 percent to $7.15 in pre-market trading. The stock has a 52-week low of $7.19, a 52-week high of $7.80 and $155.03 million in market capitalization.

Vertex Pharmaceuticals Inc. (NASDAQ:VRTX) stock declined 1.58 percent to $84.25 in pre-market trading. The stock rallied more than 60 percent in regular trading on Friday after the company announced that data from a Phase 2 study of VX-661 and ivacaftor showed statistically significant improvements in lung function among adults with cystic fibrosis (CF) who have two copies of the F508del mutation.

ArcelorMittal (NYSE:MT) stock declined 1.54 percent to $11.50 in pre-market trading. The stock has a 52-week low of $11.15, a 52-week high of $17.99 and $18.09 billion in market capitalization.

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