What is circuit breaker and how does it perform so far?

Circuit breaker is designed to pause the tradings when the violation of the market reaches a certain point in order to control the risk. This policy was announced on the 4th of December, 2015 and officially put into practice today. Based on the market performance, it is not a successful policy. It speeded up the falling speed from the circuit breaker level. The circuit breaker system does work in the US stock markets. What is going wrong in China? The traders in the Chinese stock markets look for "long" opportunities; therefore, the market is falling unexpectedly, the market has a big swing from one extreme to the other. Because the circuit breaker and the daily fluctuation limits are both designed to pause the market and limit the market bubble creation. However, when both policies are used, the markets could become easier to be paused as people rush to buy in or sell off their stocks when they realise that the markets are more likely to be paused than previously.