China’s securities regulator is targeting high-frequency traders in its latest attack on price manipulation, amid stock market turbulence that has sparked concerns over the stability of the broader financial system. The government and state-backed financial institutions have taken unprecedented measures to support the stock market after the Shanghai Composite index fell 35 per cent from a seven-year high touched on June 12, including using trillions in public funds to buy shares. The Shanghai Composite index lost 1.1 per cent on Friday and 10 per cent on the week, with most of the biggest losses occurring on Monday. The Shanghai Composite is now 29 per cent below its seven-year high and 8.6 per cent above the low point hit at the depth of the crisis on July 9. The China Securities Regulatory Commission has previously said it is tracking down “malicious” short sellers in relation to the market tumble. Friday’s action shifts the focus to algorithmic trading, which the CSRC said “amplifies gains and losses”. The Shanghai and Shenzhen stock exchanges suspended trading by 24 securities accounts that the regulator said had “influenced securities prices or investors’ decision”.