What happened to the price 15 minutes before the stock market opened?

The price 15 minutes before the opening of the stock market refers to the price generated in call auction. Before the call auction (how to generate the opening price) starts trading every day, that is, from 9: 15 to 9: 25, the Shanghai and Shenzhen Stock Exchanges begin to accept valid trading orders from shareholders. For example, the price increase and decrease must be filled in according to regulations (except for the new shares listed that day), otherwise the host will not accept it. But at this time, the computer does not match the deal. At the moment of the official opening at 9: 3, the computer mainframe of the Shanghai and Shenzhen stock exchanges began to match the transaction, and the opening price of each stock was determined by the price of the maximum turnover of each stock.

according to the regulations of the CSRC on the evening of August 6th, the closing price of stock trading is adjusted to be generated by closing call auction. The closing time of call auction is from 14:57 to 15:. The closing call auction stage can be declared, but not withdrawn. Quotes revealed the same as the opening of call auction. It has been implemented since August 2th.

call auction: call auction refers to a one-time centralized bidding method for buying and selling declarations received within a period of time. Taking China's bidding trading system as an example, the principles for determining the transaction price in call auction are as follows: 1. Select the price with the largest transaction volume within the effective price range; 2. All the buying declarations above the transaction price and the selling declarations below the transaction price are closed; 3. At least one of the buyers or sellers with the same transaction price has completed the transaction. If more than two prices meet the above conditions, the Shanghai Stock Exchange stipulates that the declared price that minimizes the volume of transactions is the transaction price. If more than two declared prices still meet the requirements, the middle price shall be taken as the transaction price. Shenzhen Stock Exchange takes the price closest to the previous closing price as the transaction price. All transactions in call auction are made at the same price. Call auction did not clinch a deal part, automatically enter the continuous bidding.

source: Baidu encyclopedia