One dollar is the same as another and one ounce of gold is the same as another. This same feature of fungibility generally applies for Bitcoin as well. That said, unlike a dollar bill or an ounce of gold, the Bitcoin’s entire history may be known at any moment since all transactions are recorded in the blockchain. As such, it is possible that certain Bitcoins used for purposes deemed illicit and/or immoral could be flagged as such and become less valuable than a “clean” Bitcoin. In the characteristic of fungibility, none of dollars, gold, or Bitcoin are perfect. All seem good enough.