Yeah I think he just might be wrong.
There wasn't previously a very good market for small and medium size investors to get near investing into early stage tech companies nationally. It has been a locked-away market. I know lots of people with single digit million dollar net-worths, none of them have a clue how to get close to interesting tech start-ups for investing purposes.
How does a person from Nebraska, worth $5 million, invest into interesting tech start-ups in Seattle? Until now, that has been extraordinarily difficult, if not impossible.
So now that there is a market for doing just that, why wouldn't prices rise on those investments? It makes perfect sense that they would, and should. Those valuations have been artificially repressed by government regulation.
What Cuban is claiming is a bubble, is more likely in fact a market being unleashed where it was previously forbidden to exist by regulation.
We're a long ways from the next Dr. Koop billion dollar valuation, with a $50+ million round of financing, coming out of crowd equity funding sites.