So what is backing this Bitcoin? Looks like a turnip bubble to me.
You need to understand what money or capital is. Capital is a social relation. Money, used as capital, is a claim over the labour power of others. When billionaires buy up bitcoin, this is what they have in mind. The labour power of those who the state prohibits from the means of subsistence and from the means of production. These people who are prohibited by the capitalist state from the use of resources, the labour potential of these people is owned by capital, and that requires enforcement by the state.
