alt Hacker NewsCrypto isn't foreign currency. The price may fluctuate wildly based on sentiment and action taken by exchanges such as Binance, which would directly impact their obligation here.
Comparing crypto to actual currency typically connected to large, real economies is not relevant here.
The crypto economy has about the same market size as a country like Russia, Italy, or Brazil.
A country like Iceland is far smaller, and their currency famously fluctuated in 2008. Would you consider Icelandic króna as money? Most people do.