The Dow Jones Industrial Average plunged by almost 500 points Thursday morning, the first day of trading after U.S. authorities secured the arrest of a Chinese technology company executive, fueling fears that the trade war with China is heating up. News broke late Wednesday that Canadian law enforcement had arrested Meng Wanzhou, chief financial officer of Huawei Technologies, a major Chinese tech firm that has been linked to the Chinese military. U.S. officials have requested her extradition, citing a suspected sanctions violation.