China’s stock exchanges on Sept 7 began soliciting public opinion on an index circuit breaker system, which would suspend trading temporarily in response to substantial drops.

The system would follow changes in the Hushen 300 Index, which reflects the performance of China’s Shanghai and Shenzhen stock exchanges, according to a draft regulation posted on the website of the Shanghai bourse.

When the index rises or falls by 5 percent, the circuit breaker would be triggered with a 30-minute suspension in stock trading.

If the index changes by 5 percent after 2:30 pm, or if the index rises or falls by 7 percent, trading would be suspended until 3 pm, the closing time for daily trading, the draft said.

China’s stock exchanges will collect opinions on the draft from now until Sept 21.