Stocks fall more than 6 percent on investors' concerns

China's stock market tumbled by more than 6 percent on Thursday, and investors' concerns about the upcoming registration-based IPO system might be a main reason, experts said.

Other factors include rising property prices in big cities, tighter liquidity in the financial system and investors' booking profits after the market's recent rebound.

The benchmark Shanghai Composite Index dropped by 6.41 percent to close at 2,741.25 points on Thursday. The Shenzhen Component Index plummeted by 7.34 percent, while the startup index ChiNext declined by 7.56 percent.