That was said when Bitcoin was $100, $1000 and $10,000. No doubt that it's a bubble in the long term, but I think you're wrong to call tops on it right now. It'll see a few corrections but it has a long way to go yet.
It's the steepness of the climb in value that is unprecedented and, frankly, unsustainable.
My fear is simply that there could be a few 'millionaires' right now that get greedy and suddenly have the value of a Mars bar in their portfolio overnight.
If it were me, I'd be setting an upper limit to get out, and as soon as it reaches it sell up and walk away happy. It's essentially the same as gambling. And again, if it were me who had invested early and was witnessing this spike, I'd be selling up and wouldn't be arsed if it went higher.