Just to highlight this concern - banning crypto trading is not what the UK FCA is looking at, crypto is fine even if regulation to some level will likely come. It's crypto derivatives that the FCA are looking at and they need to.

The main issue with derivatives and what has caused several financial meltdowns, is the difficulty in pricing the derivative as it's value is derived from an underlying asset or basket of them. If, like in the housing crisis, those underlying assets are real estate of different classes, blended into a package, bundled with interest rate products and who knows what else... the true price of the derivative and security that it represents is a nightmare to assure. Hence the outcome being a financial meltdown as even the 'professionals' have no clue.

CBF