The value of crypto-currency is derived through trading and is (almost) the same value at a specific moment , valid worldwide.
However the price quote of a crypto-asset which is most used is against so called ‘stable coins’.
It is assumed that a stable coin like USDT,USDC… is guaranteed to exchange 1:1 to fiat US dollar.
However the assumed guarantee is just a promise which may be broken and un-fulfilled as explained in detail in this article -
. The danger in the stable coins (thought experiments and the real price of Bitcoin)