Shares of Magnachip Semiconductor Corp.
MX,
+0.17%
shot up 15.8% in premarket trading Friday, after the South Korea-based chipmaker confirmed that it received an unsolicited buyout bid representing a premium of more than 50%. The company said Cornucopia Investment Partners, on behalf of itself and a group of investors, has offered to buy all of Magnachip's outstanding shares for $35 in cash, which is 51.8% above Thursday's closing price of $23.05 and would value the company at about $1.66 billion. That would top the terms of the buyout agreement with South Dearborn Ltd. announced in March, in which Magnachip agreed to be acquired for $29.00 a share in cash. Magnachip said it will "carefully review and consider" Cornucopia's bid. The stock has run up 70.5% year to date through Thursday, while the PHLX Semiconductor Index
SOX,
+1.19%
has climbed 14.3% and the S&P 500
SPX,
+0.47%
has gained 12.9%.