Pre-Market Movers; Amkor Technology up 17%

Amkor Technology (NASDAQ: AMKR) +16.95% after the company announced an exchange offer earlier today.

Nordic American Tanker Shipping (NYSE: NAT) +10.35% on the strength in the shipping industry.

Diana Shipping (NYSE: DSX) +8.78% on the strength in the shipping industry.

NXP Semiconductors (NASDAQ: NXPI) +7.07% after announcing that the company's NFC solution supports Windows 8.

Yandex (NASDAQ: YNDX) +5.32%

Ralcorp Holdings (NYSE: RAH) -10.16% after ConAgra announced it will withdraw takeover bid if no action is taken by September 19.