As he is the author of Irrational Exuberance, and craftily deconstructs how rational people bid assets to "inexplicable heights", you should begin to notice in

As he is the author of Irrational Exuberance, and craftily deconstructs how rational people bid assets to "inexplicable heights", you should begin to notice in this interview that his definition of bubble is quite broad. "Idea epidemics". By his definition, capitalism itself would be an idea epidemic, and that doesn't mean that it is going away, and that same applies to any of his bubbles. The only intention of pointing this out is that you are left at square one for finding your own validation or analysis in asset pricing, and cant defer to this authority for a conclusion in the present. Him calling something a bubble doesn't mean the asset is mispriced, is overpriced for all time, incorrectly priced, or that it will revert to a lower price. He would be an excellent commodities trader, if he stopped focusing on real estate and stock market indexes. Ebbs and flows in prices are not AT ALL controversial in the commodities market, expected even, and equally why they never caught on for retirement planning, because they can't fit into the "idea epidemic" that they go up forever. It isn't controversial that an "idea epidemic" that makes bitcoin exciting can come to a lull and lower demand. Just trade it.