China Daily quote Southwest Securities, who say:

  • Lock-up shares worth around 90.6 billion yuan ($14.6 billion) become eligible for trade on China's Shanghai and Shenzhen exchanges between July 27 and 31
  • More than 5 times the worth of shares unlocked in the past week
  • Major shareholders of non-tradable stocks are subject to one or two years of lock-up before they are permitted to trade

More on the China stock markets, here