why you asked this kind of question to be honest ?
if you do your own research i believe you should know that Bitcoin is not a bubble at this moment,
we are seeing this kind of movement due to significant increase in term of demand from other people.
lately we can see that bitcoin get recognized by some country for example japanese,
they're monitoring their exchanger for the past few months and decided to regulate it a month ago,
slowly but sure Bitcoin get approved by many people and because of that people think it's a good time to invest on it,
so what is bubble ? bubble is an asset that can be manipulated easily and do not have a solid foundation.
but Bitcoin is not that kind of asset,because even if the price pushed to the ground by the whales.
its supporter will not leave it alone and treat it as an opportunity,that mean it's zero possibility to reach $0 in the future.
so when the bubble burst ? it's not bubble and it will not burst.