People love to call these "currencies". But could you imagine if your "currency" dove 20-30% in its purchasing power within 7 days, which means your inflation/costs rose by that same percentage. Imagine if you paid 30% more for gasoline just because of your "currency" changed that much over 7 days. These are no legit currencies. They're not stable. https://s3-us-west-2.amazonaws.com/maven-user-photos/seanhyman/fundamentals/IOSU6hIfr0e_ddd3b0bprg/qFj0sMBVf0OqFN-mrC8NJg
Click on the visual to enlarge it.