many people say that bitcoin bubble, honestly I still do not understand what is meant by the term bubble earlier?
until now I am still curious
They called it bubble because bitcoin drastically increases its value in a short period of time and predicted that it will collapsed because the spikes of the value is only a results from speculation and manipulation of market behavior. Until now the bubble didnt burst and bitcoin is still functioning.
It is pure FUD from the people against bitcoin spreading wrong information to knock-out bitcoin existence.