What one factor can cause the current bull run to stop ? Like US making some law against bitcoin.
Bitcoin has always met unjust or unfair campaigns with some aggressive buys. You find people seeking to know why this and why that and when they can’t see good reason, they end up being strong investors. Though Bitcoin might dump with weak hands having to sell, that’s just skepticism at play, for people to play it safe and see how certain policies would be actioned and when it doesn’t come with the level of aggression that is expected, you find aggressive buys and the bullrun kicks in more stronger.
There really isn’t a factor really, so long as Bitcoin stays Bitcoin.