China’s toughest crackdown yet on offshore brokerages is closing a popular route to overseas markets for mainland investors. Analysts say the move is about more than investor protection. SHENZHEN: When China unveiled its toughest crackdown yet on offshore trading platforms , Beijing-based investor Elaine Liang began exploring alternatives. “The first thing I worried about was whether the trading restrictions would come immediately,” said the 30-year-old finance industry researcher, who has used