The extreme volatility observed in cryptocurrency market has raised concerns and controversies, but have mounted an exciting topic for public and industries as well as financial markets. Cryptocurrencies, however, have a weakness that could be negative influences on economic systems due to insufficient institutional control measures. Research on the recent bubbles of cryptocurrencies is crucial as it can even lead to sudden market collapse. This paper aims to empirically analyze the bubble of cryptocurrencies, the causality of the bubble, and ultimately to forecast the critical time of the bubble. In addition, we provide a framework for monitoring bubbles to diminish undesirable impacts of the bubbles in various emerging markets due to the evolution of industries along with cryptocurrencies and moot the need that policy makers ponder sentiment as a momentous factor in the related regulations.