From June to August of 20 15, the capital market in China fluctuated abnormally. After two cliff-like declines, the Shanghai Composite Index fell from 5 178. 19 to 2,850.71point in just 53 trading days, with a drop of more than 45%. This stock market crash has caused shocks at home and abroad, which has caused many disadvantages to China's social stability and smooth economic operation. The market value evaporated rapidly, from the highest point of June 20 12 178 to the lowest point of August 26, 20 15, the total market value of Shanghai and Shenzhen stock markets evaporated by about 33 trillion yuan. During the stock market crash, there were many wonders of "1000 shares falling below the limit". Because the China stock market adopts the system of plus or minus 10%, when the stock market crash occurs, there is a large-scale limit for individual stocks in the market, and the market liquidity is lacking. Many listed companies choose to suspend trading to avoid risks, and there is a "suspension tide" in the stock market to reduce losses.