SEC Freezes Trader Assets in Probe Cnooc’s Nexen Purchase

SEC Freezes Trader Assets in Probe Cnooc’s Nexen Purchase

Nelson Ching/Bloomberg

Nexen Inc.’s stock rose more than 50 percent on July 23 after CNOOC Ltd., China’s largest offshore oil and gas explorer, said that it would pay $15.1 billion in cash to acquire the Calgary-based company in the biggest overseas takeover by a Chinese firm.