I think there will be many of these Millionaires and Billionaires that will admit to owning Bitcoin, when it becomes socially acceptable to be
associated with this technology. In the early days and after Silkroad many people did not want to be known that they owned a "currency" that
were linked to drugs and child porn and all the FUD that were spread on the internet about Bitcoin. When they see other people coming out of the
cupboard... they start doing it too. After all... Bitcoin is the Best performing currency and commodity for the last 2 or 3 years now.
I don't know, a lot of investors are openly opposed to it. Warren Buffet was pretty brutal with his lack of basic understanding.
I'd say investors will take time to get involved. Those kinds of crazy returns might exist now, but that's because Bitcoin is not stable and long-term investors are unlikely to view it as secure even though the risk/reward ratio is pretty good.