Shares of SoftBank Corp began trading on Wednesday in Japan's biggest-ever IPO and one of the world's largest with shares opening 6.40 percent lower. The company is the mobile unit of billionaire Masayoshi Son's SoftBank Group holding company, which includes U.S. telecoms company Sprint. The group also holds significant stakes in Yahoo Japan and Chinese e-commerce giant Alibaba Group. SoftBank Corp raised 2.65 trillion yen ($23.5 billion) after pricing the offering at 1,500 yen a share and increased the amount of stock sold by 160 million shares in a response to strong demand, Reuters reported. That makes it Japan's ... (full story)