Is Trading212 really a halal investment platform?

The majority of Trading212 revenues come from a clearly haram source - CFDs losses. This allows them to cross-subsidise and offer commision free equities trading and free ISA accounts. If the reason they are able to offer free ISA accounts and commision free trading is because of haram and exploitative practices, is it really permissible to use their platform even if we stick to Sharia compliant equities and ETFs?

This is a genuine question for me and I am coming in with the prior that it would be better to use a platform that charges a transparent fee for trading services rather than one that doesnt charge a fee because it makes money from gambling.

Wasalam

May Allah bless you.
I do not know anything about Trading212 so my answer is a general one.
A platform created by non-Muslims, is not bound to follow shariah rules.

If however, they offer shariah compliance products, then Muslims can invest in them. If both products are connected i.e. compliant and non compliant ones, then really we need to see whether this does affect the ruling on the shariah compliant product.

But otherwise, it follows the same ruling as a non-Muslim supermarket that offers halal and haram products at the same time.

And Allah knows best!