Real wealth can be realized through a sale of the asset (or in the case of cash, judged based on the real goods it can buy). If something can never actually be

Real wealth can be realized through a sale of the asset (or in the case of cash, judged based on the real goods it can buy). If something can never actually be sold for whatever the supposed price is, then the value isn't real. The vast majority of the bubble premium could have never been realized under any scenario, and thus was not real (there wasn't even a fraction enough cash, bonds, equities, etc. to put toward realizing the real estate bubble's premium, the market could have never become actual through real sales). Only a fraction of US homes were sold during the bubble era. You can technically bid a stock to trillions in dollar worth (say Cisco goes to $25 trillion during the dotcom bubble), but you'll never be able to actually realize even a fraction of that value. And if you can't mathematically ever realize that value through a sale, then it is not actual.