The will go up in value as long as more people continue using them and the demand outpaces the creation of the supply. But once the market is saturated (i.e. the whole world) then the value of bitcoins would become stable, and would only move by market conditions such as a change in the world population, and lost bitcoins which are effectively disappearing from the system will contribute to a continued trickle of inflation.

The will go up in value as long as more people continue using them and the demand outpaces the creation of the supply. But once the market is saturated (i.e. the whole world) then the value of bitcoins would become stable, and would only move by market conditions such as a change in the world population, and lost bitcoins which are effectively disappearing from the system will contribute to a continued trickle of deflation.