Fair question!  I think this is going to be more of the 10-12 age range.  I think the book captures more about the excitement of how quick and easy Bitcoin is rather than explaining concepts about how it functions.  There is no mention of blockchains or elliptical curves.  I think it's the kind of thing where kids might want to learn more about "magical internet money" and continue to learn about it elsewhere.

It's also written in a way where if you don't really care about Bitcoin, you still get experience the young magician's excitement, disappointment, and ultimate triumph on his quest to become a great magician.