Venture capitalist Marc Andreessen went on a mini-rant on Twitter on May 7, outlining a theory of the current bubble in bubble-spotting, arguing that the quantity of analyses indicating that asset prices are in a bubble is actually a sign that there is no bubble:
I don't know that it has to be a bottom or a top, but I do think the proliferation of of people worrying about a bubble seems like a good sign that we're not in a bubble.
An aggressive asset valuation, at this point, is basically just a prediction that the next five or ten years will be better than the previous five or ten years — and the previous five and ten years have been awful. A lot of people see bubbles around because even that return to normal scenario looks too optimistic to many people. That's essentially the opposite of a cultural moment of irrational exuberance.