Authorities in China on Wednesday slapped fines on three financial information firms, including one controlled by Alibaba founder Jack Ma Yun, as part of a crackdown to stabilise stocks. Hundsun Technologies, partly owned by Ma's financial investment company, Shanghai Mingchuang Software Technology and Zhejiang Hexin Flush Network Services were fined 453 million yuan in total, with another 151 million yuan of "illicit gains" confiscated by the China Securities Regulatory Commission. "Investors were allowed to trade securities on these platforms without providing real identities," the CSRC said in a statement. "The three companies knowingly provided services to those unlicensed clients and pocketed illegal gains, creating considerable disorder in the securities market." Top executives of all three firms were handed administrative warnings along with penalties ranging between 50,000 and 300,000 yuan. The government watchdog started the probe into the firms two weeks ago. The three, through their popular cloud-based systems, connect grey-market funds such as small hedge funds and peer-to-peer lending platforms with securities brokerages. Investors could borrow up to 10 times their initial capital at an annual interest rate of up to 20 per cent to make punts through these platforms. The China Financial Futures Exchange on Wednesday said it would take further steps to curb excessive speculation in stock index futures trading, in its second tightening of rules in days. The latest market crackdown was announced after an early plunge followed by what is likely to be state-aided clawback. After falling 4.39 per cent at the open, Shanghai stocks flatlined yesterday before a four-day national holiday to commemorate the end of the second world war. The Shanghai Composite Index closed down 0.2 per cent at 3,160.17 points. Blue-chip tracker CSI300 Index closed at 3,365.83, up 0.11 per cent. In Hong Kong, the Hang Seng Index closed down 250.4 points, or 1.18 per cent, at 20,934.94. Bank shares in Shanghai led the bounce-back after the shock plunge at the open triggered by news that the government will clear another 300 to 400 billion yuan of shadow margin lending. "Must be the national team that is buying the bank shares. That's the easiest way to prop up the index before the national parade," said Nova Ji, a mutual fund manager based in Shanghai. China's markets will be closed on Thursday and Friday. The Hong Kong market will be closed Thursday but reopen Friday.