Virtual currencies are a hot topic of today. They have evolved from their first appearance in enclosed worlds of online gaming into alternative global currencies. The by far most important of them is Bitcoin with total value of more than 1 billion dollars circulating. As it differs by nature from the real currencies many political, economic and monetary questions arise. With no connection to any country or central bank, the price of Bitcoin is not backed by real economy and thus might be derived from speculation only. Still, I believe this is not true. Also, with no connection to any country, how should be Bitcoin gains taxed? I will use data from Mt. Gox, the largest Bitcoin exchange as well as Forex and NYSE data.