A Chinese billionaire who oversees one of the country’s largest investment banks has vanished, becoming the latest in a string of prominent business executives to have gone missing in mysterious circumstances. Bao Fan, 52, chairman of China Renaissance, has not been seen for three days. In a statement to the Hong Kong Stock Exchange, the company said it had not been able to connect with him, but gave no further details. His disappearance comes after Cong Lin, 56, president of China...