Yes i agree with you, but bitcoin is different because it does not have intrinsic value, so the price can rise indefinitely, Bitcoin has a price but no value. Financial bubbles only form when the price deviates significantly from intrinsic value, and then they burst.
But, if Bitcoin has no intrinsic value, only price, then the price can never deviate from value since it does not exist then it's not possible to form a bubble
It can rise indefinitely, but it can also fall to 0. Bitcoin has already been through several speculative bubbles, so I don't see how you can claim that it is not possible.
Anyway, I disagree with the statement that Bitcoin has no intrinsic value. It's intrinsic value is based on its utility. Bitcoin has utility, therefore it has intrinsic value.