Most of such rhetoric is just a word acrobatics. The confusion comes from using inappropriate words, because this phenomena needs some new words for a correct d

Most of such rhetoric is just a word acrobatics. The confusion comes from using inappropriate words, because this phenomena needs some new words for a correct description. We cannot call this a currency because having few exchanges does not make it as such. There are option exchanges and futures exchanges and other specialized institutions. It the first place, a currency cannot be this volatile, or, if so, it is a worthless currency. The current observable behavior is alike of futures and options - the price (not a value) is determined by expectations that people are holding about further movements of the price, so, basically it is a commodity futures speculation. The particular properties of the underlying technologies, such as decentralization and publicly available log of all transactions are just nice (and unique) properties, but they does not magically create any value for a bitcoin, which is just a set of unique numbers. Therefore, it is not a currency, it is a internet powered and hence globally available digital (virtual) commodity, (as worthless and dangerous as means of legal tender as derivatives) which now is in a stage of a truly global ponzi scheme, where prices are based on the pure speculation about it further movements. The usage of familiar words in a new context is what makes the ponzi scheme rolling - people make their snap-judgments based on old "rules" about "currencies" which are not appropriate for bitcoins along with peer and bandwagon effects. Very clever.