Most contracts of Shanghai Futures Exchange are limited to 8%, and the variety of night trading may be limited to 9%.

The increase of futures contracts such as cotton, corn and soybean meal is limited to less than 7%.

Commodity futures generally go up or down by 4%. When the first price limit appears, the second trade will provide a price range.

Price limit is a stable measure for China futures market. From the international experience, in order to prevent excessive speculation, most emerging financial markets adopt price limit measures, and with the development of the market, the price limit will generally be gradually relaxed (referred to as expansion).

The risk control measures of China stock market follow this idea. In fact, the development of the futures market can also learn from this experience. According to the specific situation of the market development, the range of the price limit can be gradually adjusted rhythmically, thus promoting the healthier development of the market.

If we continue to maintain the 3% price limit, the price will stop falling frequently, which will no longer be a small probability event and bring many adverse effects.

First, volatility spillover makes futures prices fluctuate greatly within a few days after the ups and downs stop, which makes it more difficult for exchanges, futures companies and investors to control risks.

Second, the delay of price discovery weakens the pricing function of the futures market, and the speed of price discovery is an important criterion to measure whether an exchange can become a pricing center.

Third, trading interference makes it unfair for traders who are willing to trade to fail, and positions that are unwilling to trade are forced to close their positions.

Once the position is closed up and down, the stop loss order cannot be executed, which is easy to cause customers to wear positions. Customers who want to hedge cannot carry out the established plan.

To make matters worse, many arbitrage markets were forced to flatten their legs in three consecutive ups and downs, forcing arbitrage transactions to become unilateral transactions, and the risks were rapidly amplified. The arbitrage between soybean and soybean meal is not big, and fear of being flattened is an important reason.