Before revision:  This study presents that it is possible to detect the potential positive and negative bubbles and crashes ahead of time, which provides a prerequisite for limiting the bubble sizes and eventually minimizing the damage from the bubble crash.
After revision:  This study is the first work in the literature that identifies the existence of bubbles in the Chinese stock market using the daily data of CSI 300 index with the advance bubble detection methodology of LPPLS confidence indicator. We have shown that it is possible to detect the potential positive and negative bubbles and crashes ahead of time, which provides a prerequisite for limiting the bubble sizes and eventually minimizing the damage from the bubble crash.