I have been curious about the case for bitcoin. A short time ago all currency was on the gold standard. Then it was loosely based on the underlying productivit

I have been curious about the case for bitcoin. A short time ago all currency was on the gold standard. Then it was loosely based on the underlying productivity of the country that issued the currency. Then it was loosely based on the underlying safety of the country that issued the currency. Even gold has bounced around in value. Having said that, I am still not convinced that bitcoin is a viable monetary standard. There is no way (that I can see) to evaluate its underlying value. Underlying value is needed for trust. Trust is needed for exchanging goods and services. Monetary standards are just stand ins for barter. Please convince me.