China’s stocks were disrupted by a huge 53% surge in trading volumes Friday due to an electronic trading error originating from state-controlled Everbright Securities (601788.SHA), Bloomberg reported. The Shanghai bourse saw its biggest intraday gain since 2009. The country’s fifth-largest brokerage detected order-generation and execution defects in an arbitrage-trading system, according to a company statement Sunday. Everbright reported an estimated loss of US$31.7 million as a result of the trading flaws. Its shares will resume trading tomorrow. China Securities Regulatory Commission is launching an investigation into the firm and Everbright faces other regulatory penalties, including a proprietary trading ban effective until November 18.