We have seen such movements. The market went down up to 20% in just 48 hours. This happened multiple times when China banned Bitcoin and Bitcoin mining a few years ago. Also, the SEC rejected Bitcoin ETF approval a couple of times. I think this is not going to happen, but let's say the USA terminates the ETF market and makes Bitcoin illegal, the market is going to crash like hell. However, considering Donald Trump is one of the crypto-friendly presidents, I don't think something like this will happen soon.