^ The fact is here. These are the difference between the fiat and the bitcoin. Aside from that you can earn or lose in holding bitcoin because it is highly volatile. If you have knowledge enough, you know how bitcoin it works and you can earn on this. While in fiat you can't ever earn while holding unless if you are depositing into the bank but the interest is too low compared to bitcoin. Nevertheless, this is the vision of Satoshi Nakamoto that the Bitcoin will be a great currency on the internet without control by the governments.