I've seen the term "unbanked" used a lot. These are consumers who don't use banks or credit unions. However, this is the first time I've seen the term "superbanked consumers". Both are considered the extremes of the two ends of the retail banking spectrum and are described in this Financial Brand blog post
The Scarborough study, “A Look Into Atypical American Banking,” set out to explore the demographics of consumers at the far extremes of either end of the retail banking spectrum: those who don’t use banks at all, and those who use banks a lot.
Superbanked are defined as consumers who have "a checking, savings, money market account and CD, and at least one of the following: stocks, options, bonds, mutual funds, money market funds, second home, investment property or other similar investments."
I'm surprised that only 5% of adults are superbanked. Based on the above definition, I would have guessed it would be closer to 20%.