The considerable diffusion of bitcoins over the Internet that took place in the last two years has highlighted some important issue about the use of anonym tools of payment in e-commerce. Even though bitcoins are largely considered to be a digital currency, the legal and economic analysis draws the attention to a concomitant structure of financial commodity with risky features related to derivative instruments making the possibility of a bubble a case to consider. The significant growth in value and the intense volatility characterizing bitcoins are more likely to be the consequence of remarkable investments made by hedge funds and the effect of specific Institutional measures, than the outcome this efficient instrument has achieved on the Internet. The following article is analyzing bitcoins in their twofold nature: the structural considerations we will express are referred to virtual coins in general, whereas the financial evaluation is related to the specific volatility of our analysis target.