There is no tax applied on bitcoin.  This is one of the reason why people loved bitcoin than fiat. If governent will consider it legal in a country and will be regulated by a government agency, then bitcoin will have a tax. If this happens, population of bitcoin may decrease. Bitcoiners choose bitcoin because it has no tax, and this tax is what they don't want. Although this tax, is the one who help our government, it just so happen that sometimes taxpayers do not feel the effect of paying taxes in the government. Cause there are government who took corruption rather than using it for its countrymen.