Bitcoin was planned as a currency. But the reality is that it functions like gold. And gold is an asset. Therefore bitcoin is also considered an asset.
We can consider bitcoin both gold as well as assets, bitcoin can not only be use for investment, but we can also use it for online shopping and so many other purposes, even bigger companies have started accepting bitcoin for their payment purposes, therefore i think that we can say that bitcoin is not only bitcoin but aw well as a crypto currency.