(Yicai Global) July 22 -- China's mainland stock markets slid at the start of the day as trading of 3.1 billion shares was unleashed on the No. 1 anniversary of the first group of initial public offerings on Shanghai's Star Market.

The Shanghai Composite Index fell 0.17 percent to 3,315.18. The Shenzhen Component Index edged down 0.21 percent to 13,507.35. The ChiNext Price Index, which tracks growth enterprises listed in Shenzhen, began at 2,725.45, down 0.4 percent.

Investors could now sell 25 Star Market-listed firms' shares that they had bought pre-IPO, with that portion worth CNY218.5 billion (USD31.4 billion).

Editor: Emmi Laine