Unless the UN or the world bank stepped in and raised alarm about the misuse of Bitcoin and got multiple countries to regulate or ban bitcoin, such a crash is unlikely at the moment. Of course that being said the volatile nature of bitcoin prices will remain until it attains a mass adoption of at least a billion users. It is likely to become more stable once and if it reaches that stage. But we can expect many countries to establish regulatory boards to curb the usage and trading of crytocurrencies even if they don't take a hard stance on banning it in its entirety. They will need to provide a very strong argument to the public and create an atmosphere of fear to stop people from thinking about using it.