Thoughts?
Most millionaires do believe in the traditional type of investment- which is either purchasing stocks or gold on the market. Since most of these investors got their wealth from a relatively risky method, some do not approve of investing into an instrument which is highly volatile (cryptocurrencies).
Though this may be the case, some big investors are jumping on the ship as they expressed their interest towards cryptocurrencies. Imagine a millionaire purchasing several hundreds of BTC. The slightest increase/decrease on its price means gain or loss of millions of $$$ on their part.