It might be a bubble; it might be waiting to pop; but nobody knows when it will pop. It could pop at $8k or it could pop at $80k. Can you afford to take that risk and not be part of the rally. This is the fear of missing out at work.
If that's what you think then please enlighten us why it is so. If it's a bubble then it has to be based on some false assumptions. What are those? That Bitcoin can't be used as a store of value that is easy to hide and move around and gives you access from various electronic devices? That it can't be used as a payment system?
When a bubble pops it goes to 0 or very close to it. People realize it's worthless. Bitcoin isn't!