How is Crypto valued? Where does the valuation come from?

Depends which crypto u are talking about. But in general, it is purely speculative. Like during the tech boom bubble, it is speculative on the project's potential 'future' prospects.

Yes, it is a bubble, but as long there is a greater fool to take the next price.

Say bitcoin, its 'intrinsic' value is essentially zero. If u need a 'floor' value, it will be the cost of generating the next bitcoin. That will depend mostly on the cost of electricity, and other cost.

These assumptions are probably true for most crypto currencies. When it comes to Bitcoin, we can already assume that it has high value and will have high value in the future. An article I can recommend:

https://medium.com/@100trillionUSD/modeling-bit...