Bismillahi rahmani raheem, assalamu alaikum.
This question has come up in the past and some fuquha have already ruled cryptocurrency is halal to use, I don’t know about Saudi Arabia but the UAE are some of the biggest investors with plans for their own currency, the country is ruled by Maliki fiqh if you don’t know.
From my perspective I have been working with the Mala’ikah for some time now looking into it and they do not have a problem with it, it is just a form of currency or commodity depending on which crypto you are using, it is not shares, all wealth and currency began with what ever value man placed upon it, this is no different.
To preempt something, I have seen from the kufar, the current economic system ruling the world is the system the Dajjal will use to strangle the world, cryptocurrency will be an extension of that, rather, not the currency but the technologies being developed as a result of it that will track everything to minute details allowing him to do that.
Life must go on so that is not a reason to avoid it, even in the time of Yajuj wa Majuj people will still go on hajj.
There are over a thousand currencies some where started by criminal organizations, do some basic research if you can’t figure out anything, Allah will not blame you for it being well hidden. Other currencies where started by some of the richest organizations in the world and have their own agenda, again that is not your concern the American dollar is owned by a country Allah calls the greater Babylon in the bible.
Almost all the major tax havens in the world where either started or developed by the “City of London”, don’t confuse that with London this is a section of the city dedicated to the elite like the Vatican is separate from Italy, with its own laws and government.
The point is these are the systems that we live under if they are inherently halal they are fine to use, but like everything else in the modern world protect yourself spiritually from any fitnah attached to it, Rasul Allah (saws) said regarding the currency everyone is using now, from it the dust of riba will enter every house.
Shaykh Rami Al Rifai.