Indeed this is a new form of Ponzi scheme, and I agree with the authors use of the "quacks-like-a-duck" model. > But if one wants to know whether bitcoin is a

Indeed this is a new form of Ponzi scheme, and I agree with the authors use of the "quacks-like-a-duck" model. > But if one wants to know whether bitcoin is a good investment, or just an old type of investment fraud with a new coat of paint, the legal definition is irrelevant. One must use a quacks-like-a-duck definition, that describes the mechanism through which fools and money are separated and the reasons why it is a fraud. It's the world's first decentralized Ponzi scheme, where each participant cell need not understand the whole picture to achieve the end result. It's a financial cancer.