There are a number of economic situations that could break and bitcoin would quickly plunge even below the 30% although some members have mentioned several of such possible occurrences but I will just want to add mine which is:

A news about Donald Trump going back on his interest in making bitcoin federal reserve for the US. Such could make bitcoin do more than a 30% dump because bitcoin reserve it's a news that has been making so much momentum for bitcoin price since Trump quest for a fed reserve, so reverse could be devastating for BTC price in less than 24hrs.