You don't have to sell bitcoin, you can borrow against it, no taxes...and you are shorting fiat. Some things are so captured by regulation, it is extremely difficult to buy with bitcoin. HODLing bitcoin IS ALSO BEING USED AS A MEDIUM OF EXCHANGE. It is a trade from your present self to your future self. The "medium of exchange" vs "store of value" argument is a false one. They are the same thing. Bitcoin cannot become a medium of exchange without being the majority of cash balances...the majority of wealth has to be bitcoin before it becomes money in the sense that it is used more transactionally.