I can imagine that quite a few billionaires have invested in bitcoin, if for no other reason than to spread out their investments. I'm sure a few have dropped a million to buy 400 bitcoins at it's current rate and they might even have bought physical crypto coins as a long term investment.
umm there are a lot of investors who invest in bitcoin to earn clear and safe profit so that they will be secure in future or by the increasing price will take them to the world of billionaires .many billionaires start their fortune through bitcoin and it gave a lot of profit to them.