Market Roundup

Shares of Power Integrations

dropped about 0.2% after the company announced its plans to buy privately held CT-Concept Technologie AG for around 105 million Swiss francs in cash, or around US$115 million, net of cash assumed. Shares of Theravance Inc

gained about 16.7% after GlaxoSmithKline PLC

announced its plans to buy 10 million shares of Theravance for around $213 million, or $21.29 per share. The deal will raise Glaxo's stake in Theravance to 27% from 18%. Shares of Analog Devices Inc

fell about 0.9% after the company reported that it has acquired Multigig Inc. The terms of the deal were not disclosed. Shares of Illumina Inc

dropped about 0.8% after the company bprojected Q1 adjusted earnings to come in at or above analysts' estimates. It expects Q1 revenue of about $270 million. However, analysts were expecting earnings of $0.31 per share on revenue of $258 million. Shares of Dell Inc

rose about 0.4% after the company announced its plans to acquire Wyse Technology, a cloud client computing firm. The terms of the deal were not disclosed.