What if the century long bubble concluded with a pop that resulted in total economic collapse? I'm not suggesting that is likely, just that the defining characteristic of a bubble seems to be the magnitude of the fallout after the pop, not the span of time leading up to the pop.
Investors, especially those of public companies, are known to be short sighted. Typical investors would never call it a "bubble" if they felt the pop wasn't for another decade, let alone a century.
Perhaps both the magnitude and the time leading up to it are of equal importance.
