The issue of stock has been resolved for a long time. The Shariah Commission publishes listings of companies to invest in.
Write a request to google "halal stock".
Yeah, stock of companies that deal with interest, alcohol, or other harams, are haram as well while investing in other stocks have no issue. Then why would Bitcoin be haram? Does bitcoin deal with interest? No. It's just another currency; people may use it for any purpose, same goes with fiat as well.
The most important question is what is money in Shariah law? Religious scholars say that "the legitimacy of money depends on its circulation among people and agreements."
Now look at the cryptocurrency situation and how it has changed over the past 3 years. Now biteoin is used not only by cypherpunks and cryptocurrency lovers, but also by states and large world exchanges.
Therefore, religious scholars do not rush to conclusions.