For me currency and asset is same . bitcoin is asset becuase many people keep it for their future money and because of this value people use this to buy anything that they want like paying bills or buy a stuff . bitcoin is currency becuase bitcoin give a profit to us .
Currently, in most countries we can't use Bitcoins directly to buy things either in any shops or online as well so I think as of now Bitcoin is only an asset or investment. If we need money then we need to sell the asset and use that money to buy other things. When we can buy things directly with bitcoins then we can consider it as a currency until that it is an asset. I know currently, we can use Bitcoins to buy some items online but still need to improve or grow a lot.
There is actually a point how Bitcoin is made on transaction. It is a form of crypto-currency that can serve as an option for people to deal with payment and transaction to a specific business. And in terms on its price, it also vulnerable on achieving development on its price, value and transaction where it could bring people a good opportunity to earn and to make profit out of their money in the future investments or tradings.