A politician should not be allowed to own something they have the explicit power to artificially inflate the value of. For the president, that’s all businesses.
As for currency, again, the president has the ability to crash the value of the American currency and drive people to his currency in order to artificially inflate it. Sacrificing an entire global economy for personal gain should not be possible.
But not only is it possible, now with the recent Supreme Court ruling, he’d be immune to prosecution for doing it, so why wouldn’t he do it?