The circuit breaker mechanism was introduced into China's stock market to provide a calming-down period for the market, to avoid or reduce hasty trading decisions in case of sharp fluctuations.It was triggered four times during the first week of trading in January after China's stock markets tumbled. China's securities regulator later suspended the new circuit breaker mechanism. This comes after the Chinese stock market witnessed its shortest trading day on Thursday.So how did the circuit breaker mechanism work? Why was it later suspended by China's financial authorities? People In the Know speaks with Liu Zhiqin, Senior Fellow of Chongyang Institute for Financial Studies, Renmin University, Einar Tangen, Former Chairman of the State of Wisconsin's International Trade Council, Cao Can, CEO of Shengya Capital as well Dermot McGrath, founding member of Sino Global Capital.