It doesn't take a massive amount of collusion. Here are the biggest Bitcoin buyers and holders. Some of them are corporations or governments. Most are from one country. And how much collusion is needed? They just need to be chasing wealth by purchasing the Bitcoin and taking it off the primary market and putting it into the paper markets. That's what they do with everything. That is their business. Once it's out of the primary market, you can't use it for cash money. You can only trade the papers, as if it were a bond.