Yes, the potential its showing now a days, bitcoin can be called as a asset. Just have a look at the worth its got, almost 6000$!! which will be increasing in the coming days for sure. So, it can be considered as a asset rather than a currency.
It serve as assets because its value appreciate over time and yield good return for those who bought them when its market value was lower as copcompared to what it is now. And it serve as a currency because one can use it to purchase an items and Bitcoin's value keeps on increasing recently with no limit in sight , bitcoin will increase year by year and you will not know how much it increases .