Chinese stock market investors have cut their borrowing by a third after a wave of margin calls and panic selling helped drive shares down by more than 30% since mid-June.

Margin debt outstanding is at its lowest level in four months, down by 810 billion yuan ($130.4 billion) from its June 18 peak of 2.27 trillion yuan. Daily new margin financing as a percentage of daily share turnover has tumbled from 19.2% in February to 5.04% on July 8, the lowest level in at least a year, according to Wind, a financial data provider.