Bitcoin is NOT a currency!
In it's simplest form it is just payment rails. Stop thinking about is as currency and what is left to regulate?
If a merchant selling a pair of jeans for $250 accepts a 1 bitcoin and customer 2 weeks later asks for a refund with a value of a bitcoin going up to $300. Is he going to get 1 bitcoin back or a value of the jeans he bought? Naturally, the value, which means 3/4 of a bitcoin at the time of the refund. So, how does it make bitcoin a currency. ITS NOT!
What do you think?
Man is it that hard to understand? He would get the same value back. ALL currencies fluctuate, the thing is Bitcoin does it a ton more since it's new.
If you bought those jeans in gold, and gold fluctuated, it would be the same thing.
A currency is a currency if it's accepted for exchange of goods and services, that's all, the rest is mental masturbation.