However, for currencies the situation is different. Owning any one currency carries a high opportunity cost of owning any other. I cannot use the same money to buy an investment in bitcoins and in silver coins or Canadian dollars. If I want more of one, I necessarily must have less of another. If any one currency is acknowledged to be the winner over the rest, then there is no additional benefit for anyone to own other currencies.
Daniel Krawisz, Why Bitcoin Will Continue to Grow