An Elon Musk joke tweet can send Dogecoin soaring for no logical reason.  But some people have become millionaires (at least for now) by buying Dogecoin.  Mark Cuban summoned up Dogecoin, "Overall, when someone brings up Dogecoin to you and asks you if it's a good investment, I would say it's not the world's best investment, but it's a whole lot better than a lottery ticket, and it's a great way to learn ...