As far as I know, bitcoin is now considered as an asset and a payment method in some country. It's a very long way for bitcoin to be a currency.
For me, I consider it as both. for long term investment of bitcoin it will be an asset. and for daily trading of your bitcoin and using it bitcoin in buying online items that accept bitcoins , I consider it as currency . so for me both, It depends actually on how you use bitcoin in your life.